Question

1. which of the following is a homogeneous mixture?

a) stainless steel
b) trail mix
c) molten iron
d) water
e) none of the above

1. which of the following items is a mixture?

a) water
b) sugar
c) brass
d) helium
e) none of the above

1. which of the following statements is false?

a) matter may be a pure substance or it may be a mixture.
b) mixtures may be composed of two or more elements, two or more compounds, or a combination of both.
c) a mixture may be either homogeneous or heterogeneous.
d) a pure substance may either be an element or a compound.
e) all of the above statements are true.

1. how would you classify raisin bran?

a) mixture-heterogeneous
b) mixture-homogeneous
c) pure substance-compound
d) pure substance-element
e) none of the above

1. a solution is an example of a (an)

a) pure substance
b) compound
c) homogeneous mixture
d) heterogeneous mixture
e) element

1. which of the following items is a physical property?

a) the combustion of gasoline
b) the odor of spearmint gum
c) the corrosive action of acid rain on granite
d) the tarnishing of a copper statue
e) none of the above

1. which of the following statements about physical and chemical changes is false?

a) phase changes are always physical changes.
b) in a physical change, matter does not change its composition.
c) in a chemical change, matter changes its composition.
d) chemical reactions are chemical changes.
e) all of the above statements are true.

Explanation:

Question 16

A homogeneous mixture has uniform composition. Stainless steel is an alloy (homogeneous mixture). Trail mix is heterogeneous. Molten iron is a pure substance (element in liquid state), water is a pure substance (compound). So the correct option is A.

A mixture consists of two or more substances. Water is a compound, sugar is a compound, helium is an element. Brass is an alloy (mixture of copper and zinc). So the correct option is C.

• Option A: Matter is either pure substance or mixture – true.
• Option B: Mixtures can have elements, compounds, or both – true.
• Option C: Mixtures can be homogeneous or heterogeneous – true.
• Option D: Pure substances are elements or compounds – true.
• So all statements are true, the false statement (if any) is none, but the option E says all are true, so E is correct? Wait, no – the question is which is FALSE. Wait, all A - D are true, so E (all above are true) is correct? Wait, no – the question is "Which of the following statements is FALSE?". So if A - D are true, then E is "All of the above statements are true" – so E is true? Wait, no, the options: A - D are true, so E is a true statement? Then there is no false statement? But the options include E. Wait, maybe I made a mistake. Wait, let's re - check:

Matter classification: pure substance (element or compound) or mixture. Mixtures can be homogeneous (uniform) or heterogeneous (non - uniform). Mixtures can be of elements, compounds, or both. So A, B, C, D are all true. So E says "All of the above statements are true" – which is true. But the question is which is FALSE. So there is a mistake? Wait, no, maybe I misread. Wait, the options: E is "All of the above statements are true". So if A - D are true, then E is true, so there is no false statement? But the question is asking for the false one. Wait, maybe the original question has a typo, but according to the options, E is the answer as all A - D are true, so E is a true statement, but the question is which is false. Wait, no, maybe I made a mistake. Wait, let's check option B: "Mixtures may be composed of two or more elements, two or more compounds, or a combination of both." – yes, for example, air has elements (O₂, N₂) and compounds (CO₂, H₂O vapor). A mixture of salt (compound) and sugar (compound) is a mixture of two compounds. A mixture of iron (element) and salt (compound) is a combination. So B is true. So all A - D are true, so E is true. But the question is which is false. So maybe the answer is E? Wait, no, E says all are true, which is true. So there is a problem? Wait, maybe the question is misprinted, but according to the options, the answer is E (since all A - D are true, so E is a true statement, but the question is which is false – maybe the intended answer is E? Or maybe I made a mistake. Anyway, according to the analysis, all A - D are true, so E is correct (as a true statement), but the question is which is false. Wait, maybe the question is "Which of the following statements is TRUE?" – but no, it's "FALSE". Anyway, following the analysis, the answer is E.

Answer:

A. stainless steel

Question 17