Question

question 19
1 pts
what does the law of multiple proportions account for?
direction of the arrow in chemical equations
subscripts in chemical formulas
coefficients in chemical equations
coefficients in chemical formulas
question 20
1 pts
what is the volume of 0.1 mole of methane (ch₄)?
(one mole of any gas occupies 22.4 l under certain conditions of temperature and pressure. assume those conditions for this question.)
22.4 l
20 l
2.24 l
44.8 l

Explanation:

Question 19

The law of multiple proportions is related to the combining of elements in different ratios to form compounds. Subscripts in chemical formulas show the ratio of atoms in a compound. For example, in \(CO\) and \(CO_2\), the sub - scripts (1 for \(O\) in \(CO\) and 2 for \(O\) in \(CO_2\)) show different ratios of \(C\) and \(O\). The direction of the arrow in chemical equations shows the direction of the reaction. Coefficients in chemical equations are for balancing the number of molecules/atoms in a reaction. Coefficients in chemical formulas are not a standard concept (subscripts are used for the ratio of atoms in a compound formula).

Step1: Use the proportion formula

If \(1\) mole of gas occupies \(V_1 = 22.4\ L\), and we have \(n = 0.1\) mole. We use the proportion \(V=n\times V_m\) (where \(V_m = 22.4\ L/mol\) is the molar volume)

Step2: Calculate the volume

Substitute \(n = 0.1\ mol\) and \(V_m=22.4\ L/mol\) into the formula \(V=n\times V_m\). So \(V=0.1\times22.4\)

$$V = 0.1\times22.4=2.24\ L$$

Answer:

subscripts in chemical formulas

Question 20