Laws of Chemical Combination

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:

• Constant proportions

• Conservation of mass

• Multiple proportions

• Reciprocal proportions

Tags

NGSS.HS-PS1-7

Which one of the following pair of substances illustrates law of multiple proportions?

• Calcium oxide and calcium hydroxide

• Sodium chloride and sodium bromide

• Carbon monoxide and carbon dioxide

• None of the above

Tags

NGSS.HS-PS1-7

A balanced chemical equation is in accordance with:

• Avogadro's law

• Law of conservation of mass

• Law of multiple proportions

• Law of reciprocal proportions

Tags

NGSS.HS-PS1-7

An unbalanced chemical reaction represents a violation of which law?

• Law of multiple proportions

• Avogadro's law

• Law of reciprocal proportions

• None of the above

Tags

NGSS.HS-PS1-7

What is the mass of one mole of water (H2O)?

• 18 g/mol

• 16 g/mol

• 1 g/mol

• 6.022x10^23 atoms

Calculate the definite proportions for H₂O

• 11% of H and 89% of O

• 50% of H and 50% of O

• 20% of H and 80% of O

• 15% of H and 85% of O

Tags

NGSS.MS-PS1-1

What was important about the law of reciprocal proportions?

• It led to our understanding of stoichiometry today

• It helped scientists discover new compounds

• It helped scientists measure compound sizes

• It helped scientists create the periodic table

Tags

NGSS.HS-PS1-7

Prove the law of multiple propotions for NO and NO₂

• It doesn't apply

• the ratio between both NO and NO₂ is 2 , therefore the law applies

• Je ne sais pas

• Miss, neta no entiendo nada

Sodium chloride, NaCl, contains 39% Na (sodium) and 61% Cl (chloride) by mass. If you have a 150-g sample of NaCl, how many grams of sodium and chloride are there in the sample?

• 10 grams of sodium and 91.5 grams of chloride

• 39% of sodium and 61% of chloride

• 58.5 grams of sodium and 91.5 grams of chloride

• 58.5 grams of soidum and 10 grams o chloride

Tags

NGSS.MS-PS1-1

Two different compounds are formed by the elements carbon and oxygen. The first compound contains 42.9% by mass carbon and 57.1% by mass oxygen. The second compound contains 27.3% by mass carbon and 72.7% by mass oxygen. Show that the data are consistent with the Law of Multiple Proportions.

• I have no clue

• 1 /2

• The multiple proportions law doesn't apply

• 2.66 / 1.33 = 2 (ratio for oxygen)

Tags

NGSS.HS-PS1-7