Sodium carbonate (naco3) is sometimes used as a water-softening agent. suppose that a worker prepares a 0.730 m solution of naco3 and water. the volume of the solution is 1.421 liters. what is the mass of solute in the solution? express your answer to three significant figures.

Answer : The mass of solute in solution is .

Solution : Given,

Molarity = 0.730 M

Volume of solution = 1.421 L

Molar mass of sodium carbonate = 105.98 g/mole

Formula used for Molarity :

where,

w = mass of solute

M = Molar mass of solute

V = volume of solution in liter

Sodium carbonate is solute and water is solvent.

Now put the given values in above formula, we get the mass of solute in solution.

By rearranging the terms, we get

Therefore, the mass of solute in solution is .

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2