How many moles of HBr are present in 250 ml of a 0.15 M HBr solution?

0.0375 moles HBr

Explanation:

we are given;

We are required to determine the number of moles;

We need to know that;

Molarity = Moles ÷ Volume

Therefore;

Moles of HBr = Molarity of HBr solution × Volume of solution

Thus;

Moles of HBr = 0.15 M × 0.25 L

                      = 0.0375 Moles

Thus, the number of moles of HBr solute is 0.0375 moles

Here we have to explain and predict the product of the reaction between hept-3-yne and bromine (Br₂)

The reaction between hept-3-yne and bromine produces trans-3,4-dibromo-3-heptene.

The reaction between the unsaturated hydrocarbon with halogen remove the unsaturation in the molecule and produces di halo compound. The reaction proceed through the formation of bromonium ion.

In this reaction as the unsaturation present in the middle of the alkyl chain i.e. hept-3-yne. The reaction will stop after the formation of di-halo compound with one double bond as shown in the figure.

The product will be exclusively trans product as the bromine is a bulky group and the formation of bromonium ion (intermediate) will be one side of the unsaturated compound.