Select all of the following equations that represent an exothermic reaction. C + 2S → CS 2, ΔH = 27,550 cal
NH 3(g) + 12.0 kcal → ½N 2(g) + 3/2 H 2(g)
CH 4 + 2O 2 → CO 2 + 2H 2O + 212,800 cal
2H 2O → 2H 2 + O 2, ΔH = +58 kcal
C (graphite) → C (diamond), ΔH = - 0.45 kcal

1.solid

2.carbon dioxide

3.helium

cytokinesis is the splitting of a cell membrane to form 2 identical daughter cells. it's similar to mitosis as both cells have identical copies of dna and cytokinesis is a step in the mitotic cycle.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2