Proportion

a compound is always composed of the same element in the same proportion by mass

• element

• law of multiple proportions

• law of definite proportions

• percent by mass

What does the law of definite proportions state in chemistry?

• It states that a compound is always composed of the same elements in the same proportion by mass.

• It states that elements can combine in different ratios to form different compounds.

• It states that the mass of reactants equals the mass of products in a chemical reaction.

• It states that the properties of elements are periodic functions of their atomic numbers.

Tags

NGSS.MS-PS1-1

Which law is used to calculate the percent composition of a compound?

• Law of conservation of mass

• Law of definite proportions

• Law of multiple proportions

• Avogadro's law

Tags

NGSS.MS-PS1-1

In a chemical reaction, the ratio of the mass of hydrogen to oxygen in water is always 1:8. What does this illustrate?

• Law of conservation of mass

• Law of definite proportions

• Law of multiple proportions

• Avogadro's law

Tags

NGSS.MS-PS1-5

Which of the following is an example of a percent proportion in biology?

• The percentage of oxygen in the atmosphere

• The ratio of red blood cells to white blood cells

• The percentage of water in the human body

• The ratio of nitrogen to oxygen in the air

In a mixture of gases, the proportion of nitrogen is 78%. What is this an example of?

• Percent by volume

• Percent by mass

• Mole fraction

• Partial pressure

The law of definite proportions states that a given chemical compound always contains the same _ in the exact same _ by mass.

• elements, compounds

• elements, molecules

• elements, proportions

• proportions, elements

Tags

NGSS.HS-PS1-7

The percentage of copper and oxygen in samples of “CuO” obtained by different methods were found to be the same. This illustrates the law of:

• definite proportion

• Conservation of mass

• Multiple proportions

• Reciprocal proportions

Tags

NGSS.MS-PS1-1

The percent by mass of carbon to oxygen in CO2 is _.

• 100%

• 33.3%

• 72.7%

• 27.3%

Tags

NGSS.MS-PS1-1

NGSS.MS-PS1-5

A:B=2/3

B:C=6:7

A:B:C=?

• 4:6:14

• 4:6:7

• 2:3:6

• 4:3:7