Answer:
0.086
Explanation:
A 5.2 molal aqueous solution of methyl alcohol indicates that 5.2 moles of methyl alcohol are present in 1 kilogram (or 1000 g) of water. Water has a molecular weight of 18 g/mol.
(100g)/18g/mol=55.56 mol
5.2 mol/(5.2mol+55.56 mol)=0.086
A) heating a pan of water until the water is all gone because then it would change from a liquid top a gas.
The grams of oxygen that are produced is 228.8 grams
<em>calculation</em>
2H₂O₂ → 2H₂O +O₂
Step 1: use the mole ratio to determine the moles of O₂
from equation above H₂O₂:O₂ is 2:1
therefore the moles of O₂ = 14.3 moles ×1/2 = 7.15 moles
Step 2: find mass of O₂
mass = moles × molar mass
= 7.15 moles × 32 g/mol =228.8 g
Answer:
3.07 Cal/g
Explanation:
Step 1: Calculate the heat absorbed by the calorimeter
We will use the following expression.
Q = C × ΔT
where,
- C: heat capacity of the calorimeter (37.60 kJ/K = 37.60 kJ/°C)
- ΔT: temperature change (2.29 °C)
Q = 37.60 kJ/°C × 2.29 °C = 86.1 kJ
According to the law of conservation of energy, the heat released by the candy has the same magnitude as the heat absorbed by the calorimeter.
Step 2: Convert 86.1 kJ to Cal
We will use the conversion factor 1 Cal = 4.186 kJ.
86.1 kJ × 1 Cal/4.186 kJ = 20.6 Cal
Step 3: Calculate the number of Cal per gram of candy
20.6 Cal/6.70 g = 3.07 Cal/g
