When sulphuric acid dissolves in water, a great deal of heat is given off. The enthalpy change for this process is called the enthalpy of solution. To measure it, 175 g of water was placed in a coffee-cup calorimeter and chilled to 10oC. Then 49.0 g of pure sulphuric acid, also at 10.0oC was added, and the mixture was quickly stirred with a thermometer. The temperature rose rapidly to 14.9oC. Assume that the value of the specific heat of solution is 4.184 J/goC. You may assume that the specific heat of the resulting sulphuric acid solution will also be 4.184 J/goC. Calculate q for the formation of this solution, and calculate the enthalpy of solution in kilojoules per mole of H2SO4.

2b2t

explanation:

2b2t

16

explanation:

the marks go by 4s

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