Given the concentration of aniline hydrochloride is 
Aniline hydrochloride is the conjugate acid of aniline a weak base.
pH can be calculated from 
anilinium ion the conjugate acid of aniline.
Balance the equation first:
2 Fe+6 HNO3→2 Fe(NO3)3+3H2
Then calculate mass of Iron :
4.5×3.0×3.5 cm3(1 mL1 cm3)(7.87 g Fe1 ml)=371.86 g Fe
Now use Stoichiometry:
371.86 g Fe×(1 mol Fe55.85 g Fe)×(6 mol HNO32 mol Fe)=19.97 mol HNO3
Convert moles of nitric acid to grams
19.97 mol HNO3×(63.01 g HNO31 mol HNO3)=1258.3 g HNO3
I think the answer is -12.7
Answer:
Because Greenhouse gases let the sun's light shine onto the Earth's surface, but they trap the heat that reflects back up into the atmosphere. And this way, they act like the glass walls of a greenhouse. This greenhouse effect also keeps the Earth warm enough to sustain life.
Explanation:
