Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.
Answer: the percent composition of carbon in heptane is 83.9%
Explanation:
<u>1) Atomic masses of the atoms:</u>
<u>2) Molar mass of heptane:</u>
- C₇H₁₆: 7 × 12.01 g/mol + 16×1.008 g/mol = 100.2 g/mol
<u>3) Mass of carbon in one mole of heptane:</u>
- C₇: 7 × 12.01 g/mol = 84.07 g/mol
<u>3) Percent composition of carbon:</u>
- % = (mass in grams of C) / (mass in grams of C₇H₁₆) × 100 =
= (84.07 g/ 100.2 g) × 100 = 83.9% ← answer
As a conjugate base of a strong acid,ClO4-would be classified as having a negligible basicity. The basicity of a chemical species is normally expressed by the acidity of the conjugate acid. The basicity of an acid is the number of hydrogen ions, which can be produced by one molecule of the acid.