In the important industrial process for producing ammonia (the haber process), the overall reaction is:
n2(g) + 3h2(g) 2nh3(g) + 100.4 kj
a yield of nh3 of approximately 98% can be obtained at 200°c and 1,000 atmospheres of pressure.
how many grams of ny must react to form 1.7 grams of ammonia, nh3?
0.052 g
1.49
0.00589
2.8 g

Explanation:

Here we have to use stoichiometry.

First of all, we have to calculate the mass of 100% of yield:

1.7 g 98%

X 100%

X = 1.73 g (approximately)

Second, we have to calculate the mass of N2 that is necessary to react to produce the mass of 1.73g of NH3. To do that, we have to use the Molar mass of N2 and NH3 and don't forget the stoichiometric relationship between them.

Molar Mass N2 : 14x2 = 28 g/mol

Molar Mass NH3: 14 + 3 = 17 g/mol

28g (N2) 17x2 (NH3)

X 1.73 g

X = 1.42 g (approximately)

most historians agree that gabriel mouton, the vicar of st. paul’s church in lyons, france, is the “founding father” of the metric system. he proposed a decimal system of measurement in 1670. mouton based it on the length of one minute of arc of a great circle of the earth (now called a nautical mile, 1852 meters). he also proposed the swing-length of a pendulum with a frequency of one beat per second as the unit of length (about 25 cm). a pendulum beating with this length would have been fairly easy to produce, thus facilitating the widespread distribution of uniform standards. over the years, his work was revised, improved, and extended by a number of french scientists.

the political sponsor of weights and measures reform in the french revolutionary national assembly was the bishop of autun, better known as talleyrand. under his auspices, the french academy appointed several committees to carry out the work of developing a usable system of weights and measures for france. one of the committees recommended a decimalized measurement system based upon a length equal to one ten-millionth of the length of a quadrant of the earth’s meridian (i.e., one ten-millionth of the distance between the equator and the north pole).