Answer:
The answer to your question is 34 g of H₂O₂
Explanation:
Data
mass of H₂O₂ = ?
mass of O₂ = 32 g
Process
1.- Write the balanced chemical reaction
H₂O₂ ⇒ H₂ + O₂
2.- Calculate the molar mass of H₂O₂ and O₂
Molar mass H₂O₂ = (1 x 2) + (16 x 2) = 34 g
Molar mass of O₂ = 2 x 16 = 32 g
3.- Use proportions to calculate the mass of O₂
34g of H₂O₂ -------------- 32g of O₂
x -------------- 32g of O₂
x = (32 x 34) / 32
x = 34 g of H₂O₂
Answer:
Mass = 88.12 g
Explanation:
Given data:
Mass of iron oxide = 126 g
Mass of iron formed = ?
Solution:
Chemical equation:
Fe₂O₃ + 3CO → 2Fe + 3CO₂
Number of moles of iron oxide:
Number of moles = mass/molar mass
Number of moles = 126 g/ 159.69 g/mol
Number of moles = 0.789 mol
Now we will compare the moles of iron with iron oxide.
Fe₂O₃ : Fe
1 : 2
0.789 : 2/1×0.789 = 1.578 mol
Mass of iron:
Mass = number of moles ×molar mass
Mass = 1.578 mol × 55.84 g/mol
Mass = 88.12 g
From other sources, the given mass of the solute that is being dissolved here is 7.15 g Na2CO3 - 10H2O. We use this amount to convert it to moles of Na2CO3 by converting it to moles using the molar mass then relating the ratio of the unhydrated salt with the number of water molecules. And by the dissociation of the unhydrated salt in the solution, we can calculate the moles of Na+ ions that are present in the solution.
Na2CO3 = 2Na+ + CO3^2-
7.15 g Na2CO3 - 10H2O (1 mol / 402.9319 g) (1 mol Na2CO3 / 1 mol Na2CO3 - 10H2O) ( 1 mol Na2CO3 / 1 mol Na2CO3-10H2O ) ( 2 mol Na+ / 1 mol Na2CO3) = 0.04 mol Na+ ions present
