Answer:
Theoretical yield of hydrogen is 1.11 g
Explanation:
Balanced equation, 
As Mg remain present in excess therefore HCl is the limiting reagent.
According to balanced equation, 2 moles of HCl produce 1 mol of 
.
Molar mass of HCl = 36.46 g/mol
So, 40.0 g of HCl = 
of HCl = 1.10 moles of HCl
Hence, theoretically, number of moles of are produced from 1.10 moles of HCl = 
Molar mass of = 2.016 g/mol
So, theoretical yield of = 
Answer:
ork out which of the displacement (S), initial velocity (U), acceleration (A) and time (T) you have to solve for final velocity (V).
If you have U, A and T, use V = U + AT.
If you have S, U and T, use V = 2(S/T) - U.
If you have S, U and A, use V = SQRT(U2 + 2AS)
Hrxn = Q reaction / mol of reaction
mol of reaction = M * V = 10 * 1 = 10 mmol = 0.01 mol
Q water = m * C * (Tf - Ti)
= (10 + 10) (4.184) (26-20) = 502.08 J
Q reaction = - Q water = -502.08 J
Hrxn = -502.08 / (0.01) = - 50208 J = - 50.21 kJ/mol
