Molarity/Dilution Questions - Help Please. (1 Viewer)

[~shinigami~]

Sorry to bother you guys but if it's possible for you to answer these questions I'm having trouble with, I'd be so grateful.

1. What volume of 0.215 mol L^-1 nitric acid is needed to react completely with 25ml 0.334 mol L^-1 sodium hydroxide?

2.What volume of 0.085 mol L^-1 is needed to react completely with 0.383g sodium hydrogen carbonate?

3. To determine the solubility of calcium hydroxide, Ca(OH)₂, a chemist took 25ml of a saturated calcium hydroxide solution and found that it reacted completely with 8.13ml of 0.102 mol L^-1 hydrochloric acid.

a) Calculate the molarity of the calcium hydroxide.

b) Calculate the solubility of calcium hydroxide in g per litre.

4. A Solution was made by dissolving 22.22g of calcium chloride in enough water to make 500ml solution. This was then reacted with 0.5 mol L^-1 sulfuric acid to produce insoluble calcium sulfate.

a) Calculate the volume of sulfuric acid needed to react.

b) Calculate the mass of calcium sulfate produced.

5. What mass of insoluble lead bromide is formed when 30ml of 0.050 mol L^-1 potassium bromide is added to an excess of lead nitrate solution?

6. A 25ml solution containing 0.033 mol L^-1 sodium chloride was needed to precipitate all of the silver from 15ml of a silver nitrate solution.

a) Calculate the concentration of the silver nitrate solution.

b) Calculate the mass of silver chloride produced.

7. The volume of 50ml of 0.242 mol L^-1 hydrochloric acid is diluted to the volume of 500ml. Calculate the molarity of the diluted solution.

I've attempted this one and I just want to check if I'm correct.
c₁V₁=c₂V₂
0.242x0.050=0.5c₂
c₂=0.0242 mol L^-1

8. 50ml 0.2 mol L^-1 sodium hydroxide was mixed with 50ml 0.3 mol L^-1 magnesium chloride. A precipitate of magnesium hydroxide formed. Calculate the concentration of:

a) sodium ions
b) magnesium ions
c) chloride ions

Sorry once again for bothering you guys with these questions. They may be simple for some but I've missed quite a few lessons and I can't grasp the concept yet.

Thank You in advance.

 

[Riviet]

I don't have much time right now but the general rule of thumb that should help you with most of these questions is write a balanced chemical equation for the reaction described and use the formulae:

number of moles = concentration (mol/L) x volume (litres)

number of moles = mass (grams) / molar mass

Don't forget about the ratios of the number of moles of the reactants/products.

 

[~shinigami~]

I don't have much time right now but the general rule of thumb that should help you with most of these questions is write a balanced chemical equation for the reaction described and use the formulae:

number of moles = concentration (mol/L) x volume (litres)

number of moles = mass (grams) / molar mass

Don't forget about the ratios of the number of moles of the reactants/products.

I appreciate you takling your time from your hectic trials schedule to help me Riviet.

It definately helped me with the questions I had.

 

[Forbidden.]

I don't have much time right now but the general rule of thumb that should help you with most of these questions is write a balanced chemical equation for the reaction described and use the formulae:

number of moles = concentration (mol/L) x volume (litres)

number of moles = mass (grams) / molar mass

Don't forget about the ratios of the number of moles of the reactants/products.

n = c V
n = m / M

EDIT: Limiting reagents, don't forget about them.