Answer:
C)We cannot be sure unless we find out its boiling point.
Explanation:
I will like to clearly state that simply comparing two compounds will not tell us exactly which one will be a liquid, solid or gas at room temperature.
If I want to determine whether an unknown substance will be a liquid at room temperature, I will have to measure its boiling point. If the boiling point is above room temperature, and the melting point is below room temperature, it’s a liquid. If the boiling point of the unknown substance is below room temperature, it is a gas.
This confirms that we cannot conclude on the state of matter in which a compound exists unless we know something about its boiling point, not by inspecting the properties of neighbouring compounds in the same homologous series
The masses can be found by substractions:
- Mass of CaSO₄.H2O (hydrate):
16.05 g - 13.56 g = 2.49 g
15.07 g - 13.56 g = 1.51 g
- The mass of water is equal to the difference between the mass of the hydrate and the mass of the anhydrate:
2.49 g - 1.51 g = 0.98 g
- The percent of water is found by the formula:
massWater ÷ massHydrate * 100%
0.98 g ÷ 2.49 g * 100% = 39.36%
- The mole of water is calculated using water's molecular weight (18g/mol):
0.98 g ÷ 18 g/mol = 0.054 mol water
- A similar procedure is made for the mole of salt (CaSO₄ = 136.14 g/mol)
1.51 g ÷ 136.14 g/mol = 0.011 mol CaSO₄
- The ratio of mole of water to mole of anhydrate is:
0.054 mol water / 0.011 mol CaSO₄ = 0.49
In other words the molecular formula for the hydrate salt is CaSO₄·0.5H₂O
<h3>
Answer:</h3>
12 moles
<h3>
Explanation:</h3>
The equation for the reaction;
CuO(s) + H₂(g) → Cu(s) + H₂O(g)
We are given;
- Moles of copper, Cu is 12 moles
We are required to calculate the number of moles of CuO required;
- From the reaction 1 mole of CuO reacts to produce 1 mole of copper
- Thus, the mole ratio of CuO to Cu is 1 : 1
- Moles of CuO = Moles of Cu
Thus, moles of CuO = 12 moles
Therefore; 12 moles of CuO will be required.
Answer:
Potassium permanganate has a molar mass of 158.04 g/mol. This figure is obtained by adding the individual molar masses of <em><u>four oxygen atoms</u></em>, <em><u>one manganese atom</u></em> and <em><u>one potassium atom</u></em>
Explanation: