FREE AND STUDY GAMES ABOUT MODULE 3 CHEMISTRY

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FREE AND STUDY GAMES ABOUT MODULE 3 CHEMISTRY

EXAM QUESTIONS

Actual Qs and Ans Expert-Verified Explanation

This Exam contains:

-Guarantee passing score -8 Questions and Answers -format set of multiple-choice -Expert-Verified Explanation Question 1: if a substance can conduct electricity when dissolved in water, what do we classify it as

Answer:

substances that conduct electricity when dissolved in water are ionic compounds

Question 2: If a substance can be decomposed, it is and element of compound

Answer:

elements cannot be decomposed, so it must be a compound Question 3: A chemist does two experiments. in one experiment, he finds that 14.0 g of nitrogen combine with 16.0 g of oxygen to make 30.0 g of a compound he calls "compound a" In another experiment, th chemist finds that 48.0 g of oxygen combine with 42.0 g of nitrogen to make 90.0 g of a compound he calls "compound b". the chemist states that the law of definite proportions tells him that "compound a" and "compound b" are two completely different compounds. why is he wrong?

Answer:

compounds a and b are really the same.... in order to make two different compounds, the elements would have to combine in different proportions. since 48.0 of oxygen and 42.0 g of nitrogen is just 3 times 16.0 g of oxygen and 14.0 g of nitrogen, the elements have combined in the same proportion so they make the same compound

Question 4: state the law of definite proportions in your own words

Answer:

a compound is always made up with the same proportion of its elements Question 5: a chemists decomposes 100.1 grams of a substance into 12.1 grams of carbon and 40.0 g of magnesium. The only other product of the decomposition was oxygen, but the gas escaped from the chemists's experimental setup. What was the mass of oxygen gas that escaped

Answer:

the law of mass conservation says that the total mass must always stay constant. must have been 48.0 g of oxygen Question 6: all scientists today believe that atoms do, in fact, exist. Has their existence been proven?

Answer:

the existence of atoms has not been proven Question 7: which theory of matter do scientists believe today: the discontinuous theory of matter of continuous theory of matter

Answer:

scientists are convinced that the discontinuous theory of matter is correct.Question 8: a substance is seen to be brittle and not conduct electricity. is it most likely a metal or a nonmetal

Answer:

it is a nonmetal