Calculations with equations involving solutions
3 marks · NormalA student dissolves 0.015 mol of silver nitrate in 100 cm³ of water.
Explain how to work out the concentration of this solution in mol/dm³. Show your calculation.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
Show answer
0.15 mol/dm³ (±0.01)
Also accept: concentration = 0.15 mol/dm³
Common mistakes: Forgetting to convert cm³ to dm³; mixing up numerator/denominator
Show mark scheme and worked solution
Marking points
M1 · 1 mark · Converts 100 cm³ to 0.1 dm³.
M2 · 1 mark · States or uses concentration = moles / volume (in dm³).
A1 · 1 mark · Correct calculation: 0.015 ÷ 0.1 = 0.15 mol/dm³. (follow-through)
Worked solution
Convert 100 cm³ to dm³: 100 ÷ 1000 = 0.1 dm³.
Concentration = number of moles / volume in dm³.