Industrial quantities - (higher tier)
Most chemical processes take place in factories. Substances are measured out in tonnes (t) and kilograms (kg), rather than in grams.
When calculating The amount of substance that contains the same number of particles as there are atoms in 12 g of carbon-12. the mass must always be expressed in grams. Here鈥檚 how to convert them:
1 tonne = 1000 kg
1 kg = 1000 g
Molar ratio in equations
A A ratio is a way to compare amounts of something. It is usually written in the form a:b. is a way to show the relationship between amounts of something.
In A chemical equation written using the symbols and formulae of the reactants and products, so that the number of units of each element present is the same on both sides of the arrow., the number in front of each formula shows the ratio of the Substances present at the start of a chemical reaction. and Substances formed in a chemical reaction.. It tells us how many moles of each chemical we need to react to make the products. If there is no number, the amount is one mole.
Example:
Zn(s) + 2HCl(aq) 鈫 ZnCl2(aq) + H2(g)
The molar ratio is:
1 mol Zn : 2 mol HCl : 1 mol ZnCl2 : 1 mol H2