Chemical calculations and Stoichiometry

What is the molarity of 4 g of NaCl (MM=58.45) in 3,200 mL of solution?

• 0.021 M

• 0.214 M

• 0.315 M

What is the molarity of a solution made by diluting 26.5 mL of 6.00M HNO₃ to a volume of 250 mL?

• 15.9 M

• 0.636 M

• 0.642 M

• 1.59 M

Correct formula for mass of an atom is

• $\frac{Avogadro's\ number}{molecular\ mass\ of\ an\ element\ \left(g\right)}$

• $\frac{Molar\ mass\ of\ a\ molecule\ \left(g\right)}{Avogadro's\ number}$

• $\frac{Molar\ mass\ of\ an\ element\ \left(g\right)}{Avogadro's\ number}$

Molecular mass is expressed in

(a)  

Molar mass of SO₂ is

• 64 a.m.u

• 64 g

• 48 a.m.u

2 moles of NH₃ contain ____________ and has molar mass ___________

• 6.022 x 10²³ molecules, 34.0 g

• 12.044 x 10²³ atoms, 34.0 g

• 12.044 x 10²³ molecules, 34.0 a.m.u

• None of these

Number of moles in 100 g of KCl (Mol. wt. = 74.5 gmol^-1)

• 1.342

• 1.452

• 1.362

In reaction $2SO_2+O_2\ \rightarrow\ \ 2SO_3$  

 0.2 moles of  product will be formed by  

• 3.2 g of Oxygen

• 32 g of Oxygen

• 1.6 g of Oxygen

• 16 g of Oxygen

Reactant that is left unreacted in a chemical reaction is called

(a)  

Amount of KCl required to produce 75 g of AgCl when treated with excess amount of AgNO₃ is (At. wt. of Ag = 108, K= 39, Cl= 35.5)

• 45.5 g

• 75 g

• 38.9 g

• 74.5 g