If a solution of 0.105 M NaOH is used to titrate 50.0 mL of a 0.0224M H₃PO₄ solution, what volume of NaOH solution in mL is required?

In the reaction of calcium carbonate with hydrochloric acid, what are the coefficients?

CaCO₃ + HCl >>>>;  CO₂ gas + CaCl₂ +  H₂O

The equilibrium constant for the reaction 

H2(g)+I2(g) >>> 2HI (g)

 is K_c = 54

If the equilibrium mixture contain 0.059 M H2 and 3.829 M HI, what is the molar concentration of I₂ at equilibrium?

acetylene is generated by the reaction 

CaC2(s)+2H2O(l)>>C2H2(g)+Ca(OH)2(aq)

If excess water is added to 34.84 g of calcium carbide, how many grams of acetylene are theoretically produced?

A pot of water containing 8.06 L of water are raised from room temperature (25.0 °C) to boiling. How much heat in kJ is required? Density of water is 1.00 g/mL , specific heat is 4.184 J/(g °C).