Koncentrácia roztokov je jedna z najdôležitejších tém v chémii, ktorá... Show more
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Updated Mar 15, 2026
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Základy koncentrácie roztokov: Riedené a koncentrované roztoky
1 / 7
Koncentrácia roztokov - základy
Predstav si, že si robíš čaj. Koľko čaju dáš do vody určuje, aký bude "silný" - to je vlastne koncentrácia! Je to spôsob, ako vyjadríme, koľko jednej látky je rozpustenej v druhej.
Aby si tomu rozumel, musíš poznať základné pojmy. Roztok je zmes dvoch látok, ktorá vyzerá ako jedna - napríklad slaná voda. Rozpúšťadlo je látka, ktorá rozpúšťa (najčastejšie voda), a rozpustená látka je to, co sa v nej rozpustí (soľ, cukor).
Roztoky môžu byť koncentrované alebo zriedené . Hmotnostný zlomok je číselný spôsob, ako presne vyjadríme koncentráciu.
💡 Tip: Voda sa nazýva univerzálne rozpúšťadlo, pretože rozpustí veľa rôznych látok!
Ako sa koncentrácia vyjadruje
Najčastejšie používame hmotnostný zlomok (w), ktorý nám ukáže pomer hmotnosti rozpustenej látky k celkovej hmotnosti roztoku. Vzorec je jednoduchý: w = hmotnosť rozpustenej látky / hmotnosť celého roztoku.
Dôležité je, že celková hmotnosť roztoku je vždy súčet hmotnosti rozpustenej látky a rozpúšťadla. Toto je častá chyba na testoch - nezabudni pripočítať obe časti!
Hmotnostný zlomok môžeš ľahko previesť na percentá - stačí ho vynásobiť číslom 100. Takže ak máš w = 0,2, koncentrácia je 20%.
💡 Pozor: Vždy používaj rovnaké jednotky - buď všetko v gramoch, alebo všetko v kilogramoch!
Riešené príklady - časť 1
Pozrime si konkrétne príklady, aby si to pochopil lepšie. Ak rozpustíš 50 g cukru v 200 g vody, celková hmotnosť roztoku bude 250 g (50 + 200).
Hmotnostný zlomok vypočítaš ako 50/250 = 0,2, čo je 20% roztok cukru. Vidíš? Nie je to až také ťažké, keď postupuješ krok za krokom.
Druhý príklad: potrebuješ 300 g 15% roztoku soli. Koľko soli a vody? Hmotnosť soli = 0,15 × 300 = 45 g, hmotnosť vody = 300 - 45 = 255 g.
💡 Kontrola: Vždy si skontroluj výsledok - súčet častí musí dať celok!
Riešené príklady - časť 2
Zriedenie roztokov je trochu zložitejšie, ale zvládneš to. Máš 100 g 25% roztoku octu a chceš ho zriediť na 5%. Koľko vody pridáš?
Najprv zistíš, koľko octu máš: 0,25 × 100 = 25 g. Táto hmotnosť octu sa nemení, len pridáš vodu. Pre 5% roztok musí byť celková hmotnosť 25/0,05 = 500 g.
Takže musíš pridať 500 - 100 = 400 g vody. Vidíš, že pridáš veľa vody, aby si dostal slabý roztok!
💡 Kľúč: Pri zrieďovaní sa hmotnosť rozpustenej látky nemení, len sa pridá rozpúšťadlo.
Dôležité tipy a poznámky
Pri riešení úloh si vždy kontroluj jednotky - to je najčastejšia chyba žiakov. Ak máš gramy a kilogramy, preveď všetko na rovnaké jednotky pred počítaním.
Koncentrácia ovplyvňuje vlastnosti roztokov. Čím je roztok koncentrovanejší, tým je napríklad sladší alebo slanší. V laboratóriu buď opatrný s koncentrovanými roztokmi!
Zapamätaj si základný vzťah: celková hmotnosť = rozpustená látka + rozpúšťadlo. Tento vzorec použiješ v každej úlohe.
💡 Na test: Precvič si výpočty hmotnostného zlomku a prepočty na percentá - to sú najčastejšie typy úloh.
Zhrnutie a opakovanie
Koncentrácia roztokov nie je ťažká, keď pochopíš základy. Roztok je zmes rozpúšťadla a rozpustenej látky, koncentrácia hovorí o ich pomere.
Hmotnostný zlomok w = hmotnosť rozpustenej látky / hmotnosť roztoku je hlavný vzorec, ktorý musíš ovládať. Na percentá ho prevedieš vynásobením 100.
Zriedené roztoky majú málo rozpustenej látky, koncentrované veľa. Pri úlohách postupuj systematicky - zisti čo máš, čo hľadáš, a použij správny vzorec.
💡 Domáca úloha: Skús vypočítať koncentráciu soli v morskej vode - skvelá príprava na test!
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
Základy koncentrácie roztokov: Riedené a koncentrované roztoky
Koncentrácia roztokov je jedna z najdôležitejších tém v chémii, ktorá ti pomôže pochopiť, koľko nejakej látky je rozpustenej v inej látke. Je to užitočné nielen pri testoch, ale aj v bežnom živote - napríklad keď si miešaš sirup alebo varíš.
Koncentrácia roztokov - základy
Predstav si, že si robíš čaj. Koľko čaju dáš do vody určuje, aký bude "silný" - to je vlastne koncentrácia! Je to spôsob, ako vyjadríme, koľko jednej látky je rozpustenej v druhej.
Aby si tomu rozumel, musíš poznať základné pojmy. Roztok je zmes dvoch látok, ktorá vyzerá ako jedna - napríklad slaná voda. Rozpúšťadlo je látka, ktorá rozpúšťa (najčastejšie voda), a rozpustená látka je to, co sa v nej rozpustí (soľ, cukor).
Roztoky môžu byť koncentrované alebo zriedené . Hmotnostný zlomok je číselný spôsob, ako presne vyjadríme koncentráciu.
💡 Tip: Voda sa nazýva univerzálne rozpúšťadlo, pretože rozpustí veľa rôznych látok!
Sign up to see the contentIt's free!
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Ako sa koncentrácia vyjadruje
Najčastejšie používame hmotnostný zlomok (w), ktorý nám ukáže pomer hmotnosti rozpustenej látky k celkovej hmotnosti roztoku. Vzorec je jednoduchý: w = hmotnosť rozpustenej látky / hmotnosť celého roztoku.
Dôležité je, že celková hmotnosť roztoku je vždy súčet hmotnosti rozpustenej látky a rozpúšťadla. Toto je častá chyba na testoch - nezabudni pripočítať obe časti!
Hmotnostný zlomok môžeš ľahko previesť na percentá - stačí ho vynásobiť číslom 100. Takže ak máš w = 0,2, koncentrácia je 20%.
💡 Pozor: Vždy používaj rovnaké jednotky - buď všetko v gramoch, alebo všetko v kilogramoch!
Sign up to see the contentIt's free!
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Riešené príklady - časť 1
Pozrime si konkrétne príklady, aby si to pochopil lepšie. Ak rozpustíš 50 g cukru v 200 g vody, celková hmotnosť roztoku bude 250 g (50 + 200).
Hmotnostný zlomok vypočítaš ako 50/250 = 0,2, čo je 20% roztok cukru. Vidíš? Nie je to až také ťažké, keď postupuješ krok za krokom.
Druhý príklad: potrebuješ 300 g 15% roztoku soli. Koľko soli a vody? Hmotnosť soli = 0,15 × 300 = 45 g, hmotnosť vody = 300 - 45 = 255 g.
💡 Kontrola: Vždy si skontroluj výsledok - súčet častí musí dať celok!
Sign up to see the contentIt's free!
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Riešené príklady - časť 2
Zriedenie roztokov je trochu zložitejšie, ale zvládneš to. Máš 100 g 25% roztoku octu a chceš ho zriediť na 5%. Koľko vody pridáš?
Najprv zistíš, koľko octu máš: 0,25 × 100 = 25 g. Táto hmotnosť octu sa nemení, len pridáš vodu. Pre 5% roztok musí byť celková hmotnosť 25/0,05 = 500 g.
Takže musíš pridať 500 - 100 = 400 g vody. Vidíš, že pridáš veľa vody, aby si dostal slabý roztok!
💡 Kľúč: Pri zrieďovaní sa hmotnosť rozpustenej látky nemení, len sa pridá rozpúšťadlo.
Sign up to see the contentIt's free!
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Dôležité tipy a poznámky
Pri riešení úloh si vždy kontroluj jednotky - to je najčastejšia chyba žiakov. Ak máš gramy a kilogramy, preveď všetko na rovnaké jednotky pred počítaním.
Koncentrácia ovplyvňuje vlastnosti roztokov. Čím je roztok koncentrovanejší, tým je napríklad sladší alebo slanší. V laboratóriu buď opatrný s koncentrovanými roztokmi!
Zapamätaj si základný vzťah: celková hmotnosť = rozpustená látka + rozpúšťadlo. Tento vzorec použiješ v každej úlohe.
💡 Na test: Precvič si výpočty hmotnostného zlomku a prepočty na percentá - to sú najčastejšie typy úloh.
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
Zhrnutie a opakovanie
Koncentrácia roztokov nie je ťažká, keď pochopíš základy. Roztok je zmes rozpúšťadla a rozpustenej látky, koncentrácia hovorí o ich pomere.
Hmotnostný zlomok w = hmotnosť rozpustenej látky / hmotnosť roztoku je hlavný vzorec, ktorý musíš ovládať. Na percentá ho prevedieš vynásobením 100.
Zriedené roztoky majú málo rozpustenej látky, koncentrované veľa. Pri úlohách postupuj systematicky - zisti čo máš, čo hľadáš, a použij správny vzorec.
💡 Domáca úloha: Skús vypočítať koncentráciu soli v morskej vode - skvelá príprava na test!
Sign up to see the contentIt's free!
Access to all documents
Improve your grades
Join milions of students
We thought you’d never ask...
What is the Knowunity AI companion?
Our AI Companion is a student-focused AI tool that offers more than just answers. Built on millions of Knowunity resources, it provides relevant information, personalised study plans, quizzes, and content directly in the chat, adapting to your individual learning journey.
Where can I download the Knowunity app?
You can download the app from Google Play Store and Apple App Store.
Is Knowunity really free of charge?
That's right! Enjoy free access to study content, connect with fellow students, and get instant help – all at your fingertips.
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4.6/5
App Store
4.7/5
Google Play
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user
The app is very easy to use and well designed. I have found everything I was looking for so far and have been able to learn a lot from the presentations! I will definitely use the app for a class assignment! And of course it also helps a lot as an inspiration.
Stefan S
iOS user
This app is really great. There are so many study notes and help [...]. My problem subject is French, for example, and the app has so many options for help. Thanks to this app, I have improved my French. I would recommend it to anyone.
Samantha Klich
Android user
Wow, I am really amazed. I just tried the app because I've seen it advertised many times and was absolutely stunned. This app is THE HELP you want for school and above all, it offers so many things, such as workouts and fact sheets, which have been VERY helpful to me personally.
Anna
iOS user
Best app on earth! no words because it’s too good
Thomas R
iOS user
Just amazing. Let's me revise 10x better, this app is a quick 10/10. I highly recommend it to anyone. I can watch and search for notes. I can save them in the subject folder. I can revise it any time when I come back. If you haven't tried this app, you're really missing out.
Basil
Android user
This app has made me feel so much more confident in my exam prep, not only through boosting my own self confidence through the features that allow you to connect with others and feel less alone, but also through the way the app itself is centred around making you feel better. It is easy to navigate, fun to use, and helpful to anyone struggling in absolutely any way.
David K
iOS user
The app's just great! All I have to do is enter the topic in the search bar and I get the response real fast. I don't have to watch 10 YouTube videos to understand something, so I'm saving my time. Highly recommended!
Sudenaz Ocak
Android user
In school I was really bad at maths but thanks to the app, I am doing better now. I am so grateful that you made the app.
Greenlight Bonnie
Android user
very reliable app to help and grow your ideas of Maths, English and other related topics in your works. please use this app if your struggling in areas, this app is key for that. wish I'd of done a review before. and it's also free so don't worry about that.
Rohan U
Android user
I know a lot of apps use fake accounts to boost their reviews but this app deserves it all. Originally I was getting 4 in my English exams and this time I got a grade 7. I didn’t even know about this app three days until the exam and it has helped A LOT. Please actually trust me and use it as I’m sure you too will see developments.
Xander S
iOS user
THE QUIZES AND FLASHCARDS ARE SO USEFUL AND I LOVE Knowunity AI. IT ALSO IS LITREALLY LIKE CHATGPT BUT SMARTER!! HELPED ME WITH MY MASCARA PROBLEMS TOO!! AS WELL AS MY REAL SUBJECTS ! DUHHH 😍😁😲🤑💗✨🎀😮
Elisha
iOS user
This apps acc the goat. I find revision so boring but this app makes it so easy to organize it all and then you can ask the freeeee ai to test yourself so good and you can easily upload your own stuff. highly recommend as someone taking mocks now
Paul T
iOS user