Sample A is 100. mL of a clear liquid. The density of the liquid is measured, and turns out to be 0.77 g/mL. The liquid is then cooled in the refrigerator. At 10.0 °C two separate clear layers form in the liquid. When the temperature is raised back to room temperature, the layers disappear. Sample B is a solid yellow cube with a total mass of 50.0 g. The cube is divided into two smaller 25.0 g subsamples, and the minimum volume of water needed to dissolve each subsample is measured. The first subsample just barely dissolved in 101. mL of water, the second in 92.0 mL. When the experiment is repeated with a new 50.0 g. sample, the minimum volume of water required to dissolve the two subsamples is 89.0 mL and 93. mL.

Required:
a. Is sample A made from a pure substance or a mixture?
b. Is sample B made from a pure substance or a mixture?

(1.6 × 10-19)(5.0 × 106) = c × 10d identify the missing numbers below to show the result of multiplying the numbers.

A1.5l container holds p.50 grams of an unknown gas at a pressure of 0.44 atm and a temperature of 50.c what is the molar mass of the unknown gas

1. an experiment in your science class lists the materials needed for the lab. it is your job, as a lab partner, to measure out 25 ml of distilled water and 2.5 grams of magnesium. what lab measuring tools would you choose to measure each substance and how would you use each tool to get the correct amounts? be sure to describe the process you would follow step-by-step. (5 points) 2.which of the following is an si base unit for measuring mass? (2 points) ampere gram meter pound 3.which of the following is an si base unit for time? (2 points) decades hours minutes seconds 4.which of the following tools should a scientist use to measure an object in milligrams? (2 points) graduated cylinder pan balance tape measure thermometer 4.which of the following tools should a scientist use to measure an object in milligrams? (2 points) graduated cylinder pan balance tape measure thermometer. 5.a pencil beside a metric ruler. the ruler is scaled from 1 centimeter to 10 centimeters, with markings for millimeters between each number. one end of the pencil is beside the 0 on the ruler, and the pencil point is beside the 5. which of the following measurements is accurate but not precise? (2 points) 5 mm 5 cm 50 mm 50 cm 6. which of the following prefixes represents the largest value? (2 points) giga hector kilo milli 7. which of the following types of graphs is best for plotting the percentages of a whole value in a data set? (2 points) bar graph circle graph histogram line graph