Question

1. which of the following is a heterogeneous mixture?

a. air
b. soil
c. salt water
d. steel

1. a cup holds 125 grams of liquid water and 100 grams of ice. what is a reasonable mass for the water in the cup after the ice melts?

a. 175g
b. 215g
c. 225g
d. 230g

1. how does water change as it evaporates?

a. its mass and volume decrease.
b. its mass and volume increase.
c. its mass remains unchanged. its volume increases.
d. its mass increases. its volume remains unchanged

1. which of the following is a heterogeneous mixture?

a. air
b. milk
c. vinegar in water
d. oil and vinegar

1. which of the following is a homogeneous mixture?

a. soil
b. salt water
c. beef stew
d. sand and water

Explanation:

Step1: Recall definition of heterogeneous mixture

A heterogeneous mixture has visibly different parts and non - uniform composition.

Step2: Analyze option a (air)

Air is a homogeneous mixture of gases like nitrogen, oxygen etc.

Step3: Analyze option b (soil)

Soil contains various components like sand, clay, organic matter etc. that are visibly distinguishable, so it is a heterogeneous mixture.

Step4: Analyze option c (salt water)

Salt water is a homogeneous mixture as salt dissolves uniformly in water.

Step5: Analyze option d (steel)

Steel is a homogeneous alloy of iron and carbon and other elements.

Answer:

1. b. soil

Step1: Apply law of conservation of mass

The total mass of water in the cup before melting (125 g liquid water + 100 g ice) is 225 g. During the phase change from ice to water, mass is conserved.