stoichiometry

The molecule

A. Unit conversion factors are used to convert between units of

grams and moles.

Explanation:In stoichiometry mass of a substance is calculated from the inter-conversion between moles and grams using conversion factors.That is, to calculate the mass of a compound or an element in a chemical equation we multiply the number of moles by the molar mass of the compound.Moles can be calculated from the mole ratio of reactants and products involved or by dividing mass of a compound by the molar mass.

A. Unit conversion factors are used to convert between units of

grams and moles.

Explanation:In stoichiometry mass of a substance is calculated from the inter-conversion between moles and grams using conversion factors.That is, to calculate the mass of a compound or an element in a chemical equation we multiply the number of moles by the molar mass of the compound.Moles can be calculated from the mole ratio of reactants and products involved or by dividing mass of a compound by the molar mass.

Answer : option b) two grams of hydrogen react with one gram of oxygen to form two grams of water.explanation :

the equation for synthesis of water is as follows;

[tex]2h_{2}_{(g)} + o_{2}_{(g)} > 2h_{2}o_{(l)}[/tex]

here two moles of hydrogen are used with one mole of oxygen which gives one molecule of water as a product. but shana misinterpreted 2 moles as 2 grams in this equation.

The answer is B :) hope this helped at least

The answer is B :) hope this helped at least

             The mole concept is important in chemistry because, "Atoms and molecules are very small and the mole concept allows us to count atoms and molecules by weighing macroscopic amounts of material".

Explanation:
                   To understand this question lets take an example of Hydrogen atom. Let suppose you need to react Hydrogen with Oxygen. You need exactly Two Hydrogen atoms and one Oxygen atom to form one water molecule.
                  The mass of 1 hydrogen atom is 1.76 × 10⁻²⁴ grams. How will you count the Hydrogen atoms??? How can you measure exactly for 1 Million Hydrogen Atoms???
                   Answer to these questions and Calculations lies in Mole. It is found that 1 Mole of Hydrogen weights exactly 1.008 gram and contains 6.022 × 10²³ atoms. Now, having this reference in hand you can calculate for any number of Hydrogen atoms.

Result:
           So the Mole helps us to zoom a microscopic level to a macroscopic level. :)