Answer:
2 a
element pure form cannot broken down
3 b
Chemical change chemical R×N
(R×N = reaction)
4c homogeneous solution
Yield = Yield (reaction yield): A measure of a chemical reaction's efficiency, as a ratio of moles of product to moles of reactant. Usually expressed as a percentage. % Yield = Moles of product.
Explanation:
When magnesium is burned, it reacts with oxygen in air not with the fire. The fire is the energy needed for the reaction to happen. Magnesium reacts with oxygen forming magnesium oxide. The light emitted from the reaction is because the reaction produced a lot of heat.
PH + pOH = 14 ⇒ pOH = 14 - pH
pOH = 14 - 2.5
pOH = 11.5
[H⁺] = 10^(-pH) = 10^(-2.5)
[H⁺] = 0.003 M
[OH⁻] = 10^(-pOH) = 10^(-11.5) = 3 × 10⁻¹² M
[OH⁻] = 3 × 10⁻¹² M
pH = 2.5 implies one significant digit
Explanation:
Since, some of the given sample is stuck inside and behind the pipet. Hence, there will occur a decrease in the percent of acetic acid.
This is because a decrease in concentration of the acid will also lead to a decrease in the amount of sample taken for the estimation. Since. lesser is the amount or concentration present lesser will be its analyte concentration.
For example, we took 10 mg of a pickel sample but 3 mg of the sample remain stuck in the pipet. This means we actually titrating a sample less than 10 mg.
Therefore, the analyte concentration in the pickel will also be less.
It would be weathering because of all the heat and pressure.
