The correct formula for hydrogen gas is H2
Answer:
A)16.3% (Hexane's formula is C6H14)
Explanation:
first one, a. lithium. it's the largest
Answer:
5.25 g NaF
Step-by-step explanation:
We know we will need a balanced equation with masses and molar masses, so let’s gather all the information in one place.
M_r: 41.99
Na₂SiO₃ + 8HF ⟶ H₂SiF₆ + 2 NaF + 3H₂O
n/mol: 8
(1) Calculate the moles of NaF
The molar ratio is 2 mol NaF/8 mol HF.
Moles of F = 0.500 mol HF × (2 mol Na₂SiO₃/8 mol HF)
Moles of Na₂SiO₃ = 0.125 mol Na₂SiO₃
(2) Calculate the mass of NaF
Mass of NaF = 0.125 mol NaF × (41.99 g Na₂SiO₃/1 mol Na₂SiO₃)
Mass of NaF = 5.25 g NaF
Answer:
39.6 g
Explanation:
The equation of the reaction is;
2Mg(s) + O2(g) --------> 2MgO(s)
To obtain the limiting reactant;
Number of moles in 26.4 g of Mg = 26.4g/24 g/mol = 1.1 moles
If 2 moles of Mg yields 2 moles of MgO
1.1 moles of Mg yields 1.1 * 2/2 = 1.1 moles of MgO
Number of moles in 26.4 g of O2 = 26.4 g/32g/mol = 0.825 moles
If 1 mole of O2 yields 2 moles of MgO
0.825 moles of O2 yields 0.825 moles * 2/1 = 1.65 moles of MgO
Hence Mg is the limiting reactant.
Theoretical yield of MgO = 1.1 moles of MgO * 40 g/mol = 44 g
Percent yield = 90%
Percent yield = actual yield/theoretical yield * 100
Actual yield = Percent yield * theoretical yield/100
Actual yield = 90 * 44/100
Actual yield = 39.6 g