## What kind of reaction is the conversion of salicylic acid to acetylsalicylic acid?

In the presence of moisture, aspirin may decompose (hydrolysis) into salicylic acid and acetic acid. This reaction is the reverse of the synthesis reaction. The maximum allowable amount of free salicylic acid in an aspirin sample is 0.15% salicylic acid.

## Can you have a negative percent change?

Percentage change can be applied to any quantity that can be measured over time. Positive values indicate a percentage increase whereas negative values indicate percentage decrease.

## How do you show a negative percentage?

1. Select the cell or cells that contain negative percentages.
2. On the Home tab, click Format > Format Cells.
3. In the Format Cells box, in the Category list, click Custom.
4. In the Type box, enter the following format: 0.00%;[Red]-0.00%.

## How do you calculate percent change when baseline is zero?

The way to compute percentage change is (new – old) / old. So, if Apr sales were 20 and May were 0, then you would get (0-20)/20 = -1, i.e., -100%. Of course, if the old were zero, then the result is undefined (or infinite depending on your preference).

## How do you find the original price after discount?

This calculation helps you to find the original price after a percentage decrease.

1. Subtract the discount from 100 to get the percentage of the original price.
2. Multiply the final price by 100.
3. Divide by the percentage in Step One.

## What is the formula for cost price if there is a profit?

Formula to calculate cost price if selling price and profit percentage are given: CP = ( SP * 100 ) / ( 100 + percentage profit). Formula to calculate cost price if selling price and loss percentage are given: CP = ( SP * 100 ) / ( 100 – percentage loss ).

## How do you find the original price after a percentage increase?

Step 1) Get the percentage of the original number. If the percentage is an increase then add it to 100, if it is a decrease then subtract it from 100. Step 2) Divide the percentage by 100 to convert it to a decimal. Step 3) Divide the final number by the decimal to get back to the original number.