Magnesium (24.30 g) reacts with hydrogen chloride (X g) to produce hydrogen gas (2.04 g) and magnesium chloride (96.90 g). How much hydrogen chloride was used in the reaction?

Explanation:

Reactants

Magnesium = 24.3 g

Hydrogen chloride= x g

Products

Hydrogen gas = 2.04 g

Magnesium chloride = 96.9 g

As the mass of the reactions is conserved we have

Mass of reactants = Mass of products

Mass of hydrogen chloride is .

in scientific notation, the value of the  speed of light in a vacuum

  will be written as 2.995 * 10^8. when this value is represented in the form of

  a * 10^b, then, a = 2.995 and b = 8.

the value of the speed of light in a vacuum given above can also be rounded up to approximately 300000000. in this case, the scientific notation will be written as 3 *10^8.