Describe exactly how you would make 150.0g of a 4.00% (w/w) solution of NaBr in water ?

4.00% w/w means 4.00 g NaBr in 100 g soln. You want 150 g soln; therefore,

4.00g NaBr x (150g/100g) = 6.00 g NaBr/150 g soln.
I would do it this way. Weigh exactly 6.00 g NaBr and place it in a container. Tare the container containing the NaBr on a balance and add water until the balance reads 150.0 grams. Check you calculations.
(mass NaBr/mass soln)*100 = (6.00/150)*100 = 4.00%

What is the mass in grams of one mole of water

Sorry I thought I was posting a question not an answer to your question!!

To make a 150.0g of a 4.00% (w/w) solution of NaBr in water, you need to follow these steps:

Step 1: Determine the amount of NaBr needed
First, calculate the mass of NaBr required to make a 4.00% (w/w) solution. The percentage means that 4.00g of NaBr is present in every 100g of the solution. To find the mass of NaBr needed, multiply the desired solution mass (150.0g) by the percentage of NaBr (4.00%):

Mass of NaBr = (Percentage of NaBr / 100) x Desired solution mass
Mass of NaBr = (4.00 / 100) x 150.0g

Step 2: Weigh the required amount of NaBr
Once you have calculated the mass of NaBr needed, weigh out that amount using a digital balance or a weighing scale.

Step 3: Prepare the solution
Add the weighed NaBr to an appropriate container (like a beaker or a flask). Then, carefully add water to the container while stirring to dissolve the NaBr completely. Make sure the final volume of the solution does not exceed 150.0g.

Step 4: Verify the concentration
To verify that you have made a 4.00% (w/w) solution of NaBr, you can calculate the actual percentage concentration by dividing the mass of NaBr by the total mass of the solution (NaBr + water) and multiplying by 100:

Actual percentage concentration = (Mass of NaBr / Total mass of solution) x 100

Make sure the actual percentage concentration is close to the desired 4.00% value.

Note: It's important to handle chemicals, especially hazardous ones like NaBr, with caution and wear appropriate safety equipment such as gloves and goggles.