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)

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

the objects have the same charge.