A stock solution is a solution of a known concentration. Stock solution has a high concentration and therefore, the known amount of stock solution is used for preparing different concentrations, by diluting the same with the known amount of the solvent being used, such as water.
There are two terms
a) accuracy : it relates to the exactness of an answer that how an answer is close to the actual answer or actual reading
So 104.6 is accurate
b) Precision : This is related to the closeness of different readings with each other
The first reading is 103.7 and the second one is 108.4 so the second reading is quite different from the first reading so it cannot be called as precised
Again 105.8 has good difference from the second reading hence again this is not precised
However the last reading 104.6 is quite near to 105.8 so 104.6 can be called as precise
The chemical element of atomic number 7, a colorless, odorless unreactive gas that forms
about 78 percent of the earth's atmosphere.
Answer: D
Explanation:
Chlorine is in group 7 or (VII) in Roman numerals, which means it has 7 balance electrons. It only needs one electron to become stable, hence it is next to the noble gases
CH₄ + 2O₂ → CO₂ + 2H₂O
From the equation, we know that methane and carbon dioxide have the same number of moles.

no. of moles of CO₂ produced = no. of moles of methane
= 4.5 × 10⁻³ ÷ (12 + 1×4)
= 2.8125 × 10⁻⁴
∴ mass of CO₂ = 2.8125 × 10⁻⁴ × (12 + 16×2)
= 12.375 × 10⁻³ g