Ammonia and oxygen react to form nitrogen and water, like this: 4NH3(g) + 3O2(g) -» N2(g) + 6H2O(g)
Imagine of 237. mmol of NH3 and 177.75 mmol of O2 of are added to an empty flask, and then answer the following questions.
1. What is the rate of the forward reaction before any NH3 or 02 has been added to the flask?
A. Zero.
B. Greater than zero, but less than the rate of the reverse reaction.
C. Greater than zero, and equal to the rate of the reverse reaction.
D. Greater than zero, and greater than the rate of the reverse reaction.
2. What is the rate of the forward reaction just after the NH3 or O2 has been added to the flask?
A. Zero.
B. Greater than zero, but less than the rate of the reverse reaction.
C. Greater than zero, and equal to the rate of the reverse reaction.
D. Greater than zero, and greater than the rate of the reverse reaction.
3. What is the rate of the forward reaction at equilibrium?
A. Zero.
B. Greater than zero, but less than the rate of the reverse reaction.
C. Greater than zero, and equal to the rate of the reverse reaction.
D. Greater than zero, and greater than the rate of the reverse reaction.
4. How much NH is in the flask at equilibrium?
A. Some, but less than.
B. 237. mmol 237. mmol.
C. More than 237. mmol.
D. None.

1. A. Zero.

2. D. Greater than zero, and greater than the rate of the reverse reaction.

3. C. Greater than zero, and equal to the rate of the reverse reaction.

4. A. Some, but less than 237. mmol.

Explanation:

Before reactants are added in a system the rate of reaction is zero. This is because, the initial rate of reaction depends on the concentration of the reacting species in the system.

When the reactants are first added, the rate of forward reaction increases rapidly and is far greater than the rate of reverse reaction.

However, at equilibrium, the rate of forward reaction is equal to the rate of reverse reaction.

At equilibrium, some NH3 has been used and some will still remain in the system because the reaction is reversible.

- calcium has greater affinity to bond with electron receptors than hydrogen does and hence, it has the ability to replace hydrogen in most of its compounds.

- lithium has 2 valence electrons in the product because it can make only 1 bond with hydrogen. beryllium has 4 valence electrons in the product because it can only make 2 bonds. it has fewer electrons than neon and can react with electron donors. each hydrogen has 2 valence electrons, the same as helium.

- the covalent bond formed between carbon and hydrogen is polar because carbon is more electronegative than hydrogen and it attracts the bonded electron pair closer to itself, thus giving hydrogen a partial positive charge.

- a hydrogen bond is a relatively weak bond that hydrogen atoms make with the electronegative atoms nitrogen, oxygen or fluorine.

so the best choice is a.) 2 calcium (ca) atoms