Answer: c. +4
Explanation:
For formation of a neutral ionic compound, the charges on cation and anion must be balanced. The cation is formed by loss of electrons by metals and anions are formed by gain of electrons by non metals.
Here manganese is having an oxidation state of +4 called as cation and oxygen forms an anion with oxidation state of -2. Thus they combine and their oxidation states are exchanged to give which written in simplest whole number ratios to give neutral
Given :
A chemical compound .
To Find :
Fix the formula for and write the full correct formula.
Solution :
We know, Potassium( K ) and Fluorine( F ) both have a valency of 1 i.e potassium can donate one electron and Fluorine can accept one electron only.
So, the chemical formula is wrong because no element has filled electron.
Therefore, to stabilise the molecule, 1 Potassium atom should make a bond from 1 Fluorine i.e KF ( correct formula ) .
Hence, this is the required solution.
Answer:
Due to the specific heat capacity of iron, 0.444 J/(g·°C), is more than the specific heat capacity for lead, 0.160 J/(g·°C)
Explanation:
The given parameters are;
The metals provided to melt the ice and their temperature includes;
One kg (1000 g) of iron;
Specific heat capacity = 0.444 J/(g·°C)
Temperature = 100°C
1 kg (1000 g) of lead
Specific heat capacity = 0.160 J/(g·°C)
Temperature = 100°C
Therefore, the heat provided to the ice of mass m, and latent heat of 334 J/g at 0°C by the metals are as follows;
For iron, we have;
ΔQ = Mass × Specific heat capacity × Temperature change
ΔQ = Heat obtained from the iron by the ice
ΔQ = 0.444 m × 1000 × (100 - 0) = 44400 J
Heat absorbed by the ice for melting, H = Heat obtained from the iron
∴ Heat absorbed by the ice for melting, H = Mass of ice × Latent heat of ice
H = Mass of ice × 334 J/g = 44400 J
Mass of ice melted by the iron = 44400 J/334 (J/g) ≈ 132.9 g
Mass of ice melted by the iron ≈ 132.9 g
For lead, we have;
ΔQ = Mass × Specific heat capacity × Temperature change
ΔQ = Heat obtained from the iron by the ice
ΔQ = 0.160 m × 1000 × (100 - 0) = 16000 J
Heat absorbed by the ice for melting, H = Heat obtained from the iron
∴ Heat absorbed by the ice for melting, H = Mass of ice × Latent heat of ice
H = Mass of ice × 334 J/g = 16000 J
Mass of ice melted by the lead = 16000 J/334 (J/g) ≈ 47.9 g
Mass of ice melted by the lead ≈ 47.9 g
Therefore, mass of ice melted by the iron, approximately 132.9 g, is more than mass of ice melted by the lead, approximately 47.9 g.