What is the absolute temperature of this gas sample when the pressure is ... The total mass of the water vapor is 0.252 g ... A silver spoon with a mass of 25.04 g at a temperature of 100.00 ... A 0.821 gram sample of pure NH F was treated with 25.0 mL of 1.00 M NaOH and heated to drive off the NH, a.

Explanation:

4 0

2 years ago

30 POINTS! ----- How many moles of oxygen gas are needed to completely react with 145 grams of aluminum? Report your answer with

gladu [14]

First a balanced reaction equation must be established:
$4Al _{(s)} + 3 O_{2} _{(g)}$ → $2 Al_{2} O_{3}$

Now if mass of aluminum = 145 g
the moles of aluminum = (MASS) ÷ (MOLAR MASS) = 145 g ÷ 30 g/mol
= 4.83 mols

Now the mole ratio of Al : O₂ based on the equation is 4 : 3
[4Al + 3 O₂ → 2 Al₂O₃]

∴ if moles of Al = 4.83 moles
then moles of O₂ = (4.83 mol ÷ 4) × 3
= 3.63 mol (to 2 sig. fig.)

Thus it can be concluded that 3.63 moles of oxygen is needed to react completely with 145 g of aluminum.

4 0

2 years ago