Answer:
0.1828g/cm³
Explanation:
density= mass÷volume
m= 12.6g
v= 4.1×4.1×4.1 = 68.921cm³
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density= 12.6÷68.921 = 0.1828g/cm³
D. paper d, paper c, paper a, paper b
It describes the point at which the element is a solid liquid and has at a certain temperature and pressure
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
A reaction in which Oxygen (O₂) is produced from Mercury Oxide (HgO) would be a decomposition reaction.
2HgO → 2Hg + O₂
If 250g of O₂ is needed to be produced,
then the moles of oxygen needed to be produced = 250g ÷ 32 g/mol
= 7.8125 mol
Now, the mole ratio of Oxygen to Mercury Oxide is 1 : 2
∴ if the moles of oxygen = 7.8125 mol
then the moles of mercury oxide = 7.8125 mol × 2
= 15.625 mol
Thus the number moles of HgO needed to produce 250.0 g of O₂ is 15.625 mol
