HELPPPP! Please explain all answers 1) How many grams of potassium periodate (KI

Question

HELPPPP! Please explain all answers

1)

How many grams of potassium periodate (KIO4) should be added to a 250 mL volumetric flask to prepare a 0.5605 M solution when the flask is diluted to the mark with water?

2) Carbon dioxide and water form during combustion of methane. How many grams of water vapor form when 2.39 g of methane react completely with excess oxygen?

CH4(g) + 2 O2(g) CO2(g) + 2 H2O(g)

3) A sample of lead ore was analyzed for lead content by dissolving 4.9770 g of the ore in sulfuric acid solution. The resultant reaction produced a precipitant of lead sulfate, which was isolated by filtering, washing and drying. If 0.5823 g of lead sulfate was obtained, what was the mass percentage lead in the sample

Explanation / Answer

1)

KIO4

grams needed for

V = 250 ml and M = 0.5605 solution

M = mol/V

mol = M*V = 0.5605*0.25= 0.140125 mol ofKIO

mass = mol*MW = 230*0.140125 = 32.228 g of KIO4 are neede

2)

find moles of methane first

Mol = mass/MW = 2.39/16 = 0.149375 mol of CH$

1 mol of methane produces 2 mol of water

therefore 2*0.149375 = 0.29875 mol of water

mass = mol*MW = 0.29875*18 = 5.3775 g of water weill be produced

3)

m = 4.977 g of ore

m = 0.5823 g of PbSO4

% sample = mass of sample / total mass * 100 = 0.5823/4.977 * 100 = 11.69981 %

Related Questions

Navigate

• Browse (All)
• Browse H
• Subjects

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.