13. D
14. A
15. C
16. B
17. F
18. E
Because in SI, the expectation is that area and volume will be expressed in terms of a linear dimension( the metre) or its multiples.
Explanation:
Sodium Chloride or NaCl is made up of two elements, sodium (or Na) and chlorine (or Cl). A molecule of sodium chloride, NaCl, consists of one atom each of sodium and chlorine. Hence, each molecule of NaCl has 2 atoms total.
Answer is: 4) The same subscripts are on each side of the equation.
For example, balanced chemical reaction:
2Mg + O₂ → 2MgO.
1) The same number of atoms is on each side of the equation: two magnesium atoms and two oxgen atoms.
2) The formulas for all substances are correct: in magnesium oxide (MgO), magnesium has oxidation number +2 and oxygen -2, so formula is good, because compound must be neutral.
3) The same mass is represented on each side of the equation: because there is same number of atoms, the mass is the same.
4) The same subscripts are on each side of the equation: oxygen does not have same subscripts.
Answer:
(D) Neither I nor II
Explanation:
The reagent potassium hydrogen phthalate is found in pure form and it is not partially hydrated .
The pallet form of NaOH ( solid form ) absorbs carbon dioxide gas from the atmosphere but NaOH in solution form does not absorb carbon dioxide .
Hence option D ) is right choice .
