D protons. <span>the identity of an element is determined by the total number of protons present in the nucleus of an atom contained in that partial element.
._.</span>
Answer:
0.96g of sodium hydride
Explanation:
Equation of reaction:
NaH + H20 = NaOH + H2
Mass of hydrogen gas produced (m) = PVM/RT
P = 765torr - 28torr = 737torr = 737/760 = 0.97atm, V = 982mL = 982cm^3, M = 2g/mol, R = 82.057cm^3.atm/gmol.K, T = 28°C = 28 + 273K = 301K
m = (0.97×982×2)/(82.057×301) = 0.08g of hydrogen gas
From the equation of reaction
1 mole (24g) of sodium hydride produced 1 mole (2g) of hydrogen gas
0.08g of hydrogen gas would be produced by (24×0.08)/2 = 0.96g of sodium hydride
Answer:
9.1 KJ
Explanation:
First we must find the number of moles of HBr involved;
number of moles of HBr= mass of HBr/ molar mass of HBr
But molar mass of HBr= 80.91 g/mol
Given mass of HBr from the question= 20.1g
Hence;
Number of moles of HBr= 20.1 g/80.91g
Number of moles of HBr= 0.25 moles of HBr
If 2 moles of HBr has a heat of formation of 72.80KJ
Then 0.25 moles of HBr will have a heat of formation of 0.25× 72.80/2= 9.1 KJ
Therefore; 20.1 g of HBr will have a heat of formation of 9.1 KJ
