How do you do this question? - OCR Chem A
Hi I was struggling with this question and was wondering if anyone could help -
This question looks at groups in the periodic table. (a) Calcium and strontium are Group 2 metals. They both react with water. A chemist reacts 0.200 g of strontium with 250 cm3 water, leaving a colourless solution containing strontium ions. The volume remains at 250 cm3.
Calculate the concentration, in mol dm–3, of strontium ions in the resulting solution.
This question looks at groups in the periodic table. (a) Calcium and strontium are Group 2 metals. They both react with water. A chemist reacts 0.200 g of strontium with 250 cm3 water, leaving a colourless solution containing strontium ions. The volume remains at 250 cm3.
Calculate the concentration, in mol dm–3, of strontium ions in the resulting solution.
Equation is: Sr(s) + 2H2O(g) → Sr(OH)2(aq) + H2(g). We can work out the number of moles by using mol=mass/Mr. Mr of Strontium = 87.6. Therefore, 0.200/87.6 = 0.00228 (3.s.f). Therefore, there are 0.00228 mol of Sr(OH)2, as the mole ratio is 1:1 in the equation.
To find the conc. of the Sr(OH)2, we can use mol=conc. x vol., rearranged to give conc. = mol./vol.. As the question has told you that you have 250cm3 of solution at the end, we can do conc. = 0.00228/0.25 = 0.00913 mol dm-3.
Hope this helps! (I think I've done it correctly...no guarantees though!)
To find the conc. of the Sr(OH)2, we can use mol=conc. x vol., rearranged to give conc. = mol./vol.. As the question has told you that you have 250cm3 of solution at the end, we can do conc. = 0.00228/0.25 = 0.00913 mol dm-3.
Hope this helps! (I think I've done it correctly...no guarantees though!)
Original post by gd99
Equation is: Sr(s) + 2H2O(g) → Sr(OH)2(aq) + H2(g). We can work out the number of moles by using mol=mass/Mr. Mr of Strontium = 87.6. Therefore, 0.200/87.6 = 0.00228 (3.s.f). Therefore, there are 0.00228 mol of Sr(OH)2, as the mole ratio is 1:1 in the equation.
To find the conc. of the Sr(OH)2, we can use mol=conc. x vol., rearranged to give conc. = mol./vol.. As the question has told you that you have 250cm3 of solution at the end, we can do conc. = 0.00228/0.25 = 0.00913 mol dm-3.
Hope this helps! (I think I've done it correctly...no guarantees though!)
To find the conc. of the Sr(OH)2, we can use mol=conc. x vol., rearranged to give conc. = mol./vol.. As the question has told you that you have 250cm3 of solution at the end, we can do conc. = 0.00228/0.25 = 0.00913 mol dm-3.
Hope this helps! (I think I've done it correctly...no guarantees though!)
Great thanks!
Original post by Alfieee
Great thanks!
You're welcome.
Original post by gd99
Equation is: Sr(s) + 2H2O(g) → Sr(OH)2(aq) + H2(g). We can work out the number of moles by using mol=mass/Mr. Mr of Strontium = 87.6. Therefore, 0.200/87.6 = 0.00228 (3.s.f). Therefore, there are 0.00228 mol of Sr(OH)2, as the mole ratio is 1:1 in the equation.
To find the conc. of the Sr(OH)2, we can use mol=conc. x vol., rearranged to give conc. = mol./vol.. As the question has told you that you have 250cm3 of solution at the end, we can do conc. = 0.00228/0.25 = 0.00913 mol dm-3.
Hope this helps! (I think I've done it correctly...no guarantees though!)
To find the conc. of the Sr(OH)2, we can use mol=conc. x vol., rearranged to give conc. = mol./vol.. As the question has told you that you have 250cm3 of solution at the end, we can do conc. = 0.00228/0.25 = 0.00913 mol dm-3.
Hope this helps! (I think I've done it correctly...no guarantees though!)
Thanks I was looking all over for this answer too!
Quick Reply
Related discussions
- Study Buddy
- How to get A* at OCR A level chemistry?
- Medicine resit reapplicants 2023
- Biomedical engineering a levels???
- Ocr chemistry a exam-style questions
- Any last minute A level tips?
- ocr as level biology paper 2 2022
- A level revision notes and advice
- About 3 weeks until A-Level exams HELP
- HELP im horrible at module 2 OCR chemistry
- advice for C in a level bio and chem?
- better late than never - gyg 24' :)
- Study buddy for a levels
- Looking for a study buddy!
- intro
- How do I study and revise Year 13
- Final Year A level Academic Comeback 2024
- AQA A level Chemistry June 2022 Papers
- Ask me anything (a student w all 9s)
- A level predicted grades
Latest
Trending
Last reply 6 days ago
Im confused about this chemistry question, why does it form these productsTrending
Last reply 6 days ago
Im confused about this chemistry question, why does it form these products
