How many moles are in 15.62g of P?

Explanation:

To convert from moles to grams, we must use the molar mass. This is found on the Periodic Table. Look for Phosphorous or P.

We can use this number as a ratio.

Multiply by the given number of grams: 15.62

Flip the fraction so the grams of phosphorus cancel.

Divide.

The original measurement of grams has 4 significant figures, so our answer must have the same.

For the number we calculated, that is the ten thousandth place. The 9 in the hundredth thousandth place tells us to round the 2 to a 3.

There are 0.5043 moles of phosphorus in 15.62 grams.

answer : one can design an experiment using a liquid and an additive that can be added to the liquid and observe the chemical changes in the reaction species.

one would need a beaker which is filled with a known amount of the liquid in which thermometer is placed to measure the temperature changes; after addition of the additive to the liquid solution one can note down the temperature change and find whether the reaction is endothermic or exothermic in nature. by subtracting the initial temperature value with the final temperature one can find the temperature changes.

various combinations of liquid and additive can be used. liquid in this case can be a known quantity of water and additives can be epsom salt or without epsom salt the experiment can be conducted to notice the changes. water and ice, hydrogen peroxide and dry yeast, vinegar and baking soda,etc.