When performing a multiplication or division calculation, significant figures in the calculated result are dictated by the of the measured numbers. The calculated result should have the measured number in the calculation with the fewest .

Explanation:

When performing a multiplication or division calculation, significant figures in the calculated result are dictated by the significant figures of the measured numbers. The calculated result should have the same significant figure as the measured number in the calculation with the fewest significant figures.

According to the rule guiding significant figures during mathematical operations; when performing multiplications or divisions involving multiple numbers, the final answer should have the same significant figures as the number with the least significant figures.

For example: if 10.54 and 101.25 are multiplied, the final answer should have the same significant figure as 10.54 because this is the number with the least significant figure among the numbers involved in the entire operation.

10.54 has 4 significant figures while 101.25 has 5 significant figures. The final answer should, therefore, have 4 significant figures.

Thus; 10.54 x 101.25 = 1,067

the equation that correctly represent the reaction for formation of ammonia is

n2+ 3h2 → 2nh3 (answer d)

1 mole of nitrogen gas (n2) react with 3 moles of hydrogen gas (h2) to form 2 moles of ammonia ( nh3). this is in a process known as haber process were iron is used as a catalyst and reaction take place that a higher temperature and pressure. the process is exothermic hence energy is released.

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