Testing article

Testing 1:

Key points

Common names	Molecular formula
Baking soda	${NaHCO}_{3}$ ‍
Washing soda	${Na}_{2} {CO}_{3} .10 H_{2} O$ ‍
Bleaching powder	${CaOCl}_{2}$ ‍
Gypsum	${CaSO}_{4} . 2 H_{2} O$ ‍
Plaster of paris	${CaSO}_{4} . \frac{1}{2} H_{2} O$ ‍
Hydrated copper sulphate	${CuSO}_{4} . 5 H_{2} O$ ‍

Introduction

From the baking soda used in making fluffy cakes to washing soda used in the detergents, salts are everywhere! But how do we even remember their molecular formula? In order to answer this, we need to know their common names and the steps we follow to memorize the molecular formula. In this article, we focus on how to memorize and remember the molecular formula of salts from their common names.

Baking soda

What is the molecular formula of baking soda?
Answer:___.

It's ok if we cannot answer this right away. Let's follow the steps below and try to answer.

In order to answer this, we need to know the chemical name of baking soda.
Baking soda is chemically called sodium bicarbonate or sodium hydrogen carbonate.
Let's try splitting it into three words.
Now let's write the symbol for each word (atom/molecule/compound).
Now let's write the charge on each symbol.
Now let's balance the charges.
Let's arrive at the molecular formula by combining them together.

Sodium	hydrogen	carbonate
$Na$ ‍	$H$ ‍	${CO}_{3}$ ‍

Sodium	hydrogen	carbonate
${Na}^{+}$ ‍	$H^{+}$ ‍	${CO}_{3}^{2 -}$ ‍
+1	+1	-2

Sodium	hydrogen	carbonate
${Na}^{+}$ ‍	$H^{+}$ ‍	${CO}_{3}^{2 -}$ ‍
+1	+1	-2

Testing 2:

Write the molecular formula of the compounds given below in apiece of paper and check your answers.

Give yourselves one point if the answer is correct in the rightmost box. If it is wrong it's ok. Leave it blank.

Common names	Molecular formula	points
Baking soda		Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Washing soda		Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Bleaching powder		Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Gypsum		Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Plaster of paris		Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍
Hydrated copper sulphate		Your answer should be an integer, like $6$ ‍ a simplified proper fraction, like $3 / 5$ ‍ a simplified improper fraction, like $7 / 4$ ‍ a mixed number, like $1 3 / 4$ ‍ an exact decimal, like $0.75$ ‍ a multiple of pi, like $12 pi$ ‍ or $2 / 3 pi$ ‍

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