Answer:
1249.88 mol.
Explanation:
∵ no. of moles of Fe = mass of Fe/atomic weight of Fe.
<em>∴ no. of moles of Fe </em>= (6.98 x 10⁴ g)/(55.845 g/mol) = <em>1249.88 mol.</em>
Answer: 17) d. 
18. c. The empirical formula of a compound can be twice the molecular formula.
Explanation:
Molecular formula is the chemical formula which depicts the actual number of atoms of each element present in the compound.
Empirical formula is the simplest chemical formula which depicts the whole number of atoms of each element present in the compound.
To calculate the molecular formula, we need to find the valency which is multiplied by each element to get the molecular formula.
The equation used to calculate the valency is:

The empirical mass can be calculated from empirical formula and molar mass must be known.
17. Thus the empirical formula of
should be 
18. The molecular formula will either be same as empirical formula or is a whole number multiple of empirical formula. Thus the empirical formula of a compound can never be twice the molecular formula.
I think it is c but I’m not sure
Answer:
Taq polymerase is a thermostable which states that it can even work at higher temperature. The main function of using this enzyme is that it is used to amplify the DNA which will help in producing ample amount of DNA sample.
The enzyme activity is temperature dependent. The denaturation and annealing steps of the PCR occurs at very high temperature.
Any other enzyme used at such an high temperature would have decreased the enzyme activity and the procedure would not be completed.