Bromine and nitrogen combine to form nitrogen tribromide (NBr3). How many liters of NBr3 gas are produced when 6.85 L of bromine reacts with excess nitrogen? Assume conditions are at STP.

4.567 ltr

Explanation:

both are gases

so

N2 +Br2 =NBr3

balancing

N2 +3B2 = 2 NBr3

now

3 litr of B2 gives 2 liter of NBr3

6.85 litr of B2 gives 2/3 *6.85 litr NBr3 = 4.567ltr

answer: c. the experiment shows that the red substance experienced a chemical change.

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e