Given the heats of combustion of ethylene, hydrogen and ethane as 337.2, 68.3 and 372.8 kcal respectively, calculate the heat of reaction at 78°C for;
C2H4(g) + H2(g) → CH.(g)
[9 marks]​

What is another way to determine mass times acceleration?

The data below were determined for the reaction shown below. s2o82– + 3i – (aq) → 2so42– + i3– expt. # [s2o82–] (m) [i –] (m) initial rate 1 0.038 0.060 1.4 × 10 – 5 m/s 2 0.076 0.060 2.8 × 10 – 5 m/s 3 0.076 0.030 1.4 × 10 – 5 m/s the rate law for this reaction must be:

The point along a planet's orbit where it is closest to the sun is called the