Matter and Measurement

A ball has a mass of 250g and a volume of 100cm3. What is its density? Choose only ONE best answer. A) 0.4g/cm3 B) 2.5g/cm3 C) 4g/cm3 D) 25g/cm3 E) 25,000g/cm3

2.5g/cm3

Which of the following is a pure substance? I. NaCl II. O2 III. H2O or All the above

All of the above. A pure substance is any single element or single compound whereas a mixture contains two or more substances. These are all pure substances as NaCl and H2O are each single compounds and O2 is a single element.

If a block of ice has a mass of 91g and a volume of 100cm3, what would be the mass of a block of ice with a volume of 20cm3? A) 4.55g B) 18.2g C) 91g D) 182g E) 455g

B) 18.2g

Convert 376nm to millimeters. A) 3.76 x 10-3mm B) 3.76 x 10-4mm C) 3.76 x 10-5mm D) 3.76 x 10-6mm E) 3.76 x 10-7mm

B) 3.76 x 10-4mm

Which of the following is a pure substance? A) Salt water B) Orange juice C) Coca Cola D) Ammonia E) Air

B) Ammonia All of theses are mixtures except for ammonia (NH3) which is a single compound. Salt water contains two substances, salt and water. Orange juice contains a variety of substances including water and ascorbic acid. Coca Cola contains a variety of substances including water, phosphoric acid, sugar (or high fructose corn syrup), etc. Air is a mixture of gases including N2, O2, and trace amounts of a number of other gases.

Which of the following is a pure element? A) Ice B) Oxygen gas C) Aqueous hydrochloric acid D) Carbon dioxide gas E) Sodium chloride

B) Oxygen gas (O2) is the only element listed. Ice (H2O) is a compound. Aqueous hydrochloric acid is a mixture of water and HCl. Carbon dioxide gas (CO2) is a compound. Sodium chloride (NaCl) is a compound.

Convert 250cm3 to liters (1cm3 = 1mL). Choose only ONE best answer. A) 0.0025L B) 0.025L C) 0.25L D) 2.5L E) 2500L

C) 0.25L

Convert 13ft to meters (1in = 2.54cm). A) 0.028m B) 0.61m C) 4.0m D) 43m E) 40,000m

C) 4.0m

Which of the following is a chemical change? A) water boiling B) salt dissolving in water C) metal rusting D) melting iron E) hail formation in the atmosphere

C) Metal Rusting A chemical change occurs when a substance is converted into a different substance. When metal rusts iron combines with oxygen to form iron oxide and so a chemical change indeed occurs. Phase changes are physical changes as the same substance still exists, just in a different phase. Water boiling, iron melting, and hail formation are all just phase changes. Salt dissolving in water can also be considered a phase change and is simply a physical change; there is no conversion of one substance into another. It is the same subtance before and after dissolving. NaCl(s) → NaCl(aq)

Which of the following is an extensive property? A) melting point B) density C) volume D) temperature E) boiling point

C) Volume An extensive property is one that depends upon the size of the sample of interest, whereas an intensive property is one that does not depend on the size of the sample of interest. The volume of a substance depends upon how much of that substance one has and is therefore an extensive property. The remaining properties listed would all be the same for a substance regardless of the amount of that substance being examined and are therefore intensive properties.

Convert 0.37L to nanoliters. A) 3.7 x 10-10nL B) 3.7 x 10 2nL C) 3.7 x 10 5nL D 3.7 x 10 8nL E) 3.7 x 10 11nL

D 3.7 x 10 8nL

Which of the following is a homogeneous mixture? A) Liquid water B) A pepperoni pizza C) A can of paint D) Air E) Liquid nitrogen

D) Air A homogeneous mixture is a combination of two or more substances in which the composition is uniform throughout. Air is a mixture of several gases (mostly O2 and N2) and the composition is uniform throughout making it a homogeneous mixture. Liquid water is a single substance (a single compound) rather than a mixture. A pepperoni pizza is a heterogeneous mixture rather than homogeneous as its composition is NOT uniform throughout (some bites you might get some pepperoni, some you might not). A can of paint is a heterogeneous mixture rather than homogeneous as its composition is NOT uniform throughout (the components separate as it settles which is why it must be mixed before using). Liquid nitrogen a single substance (a single element) rather than a mixture.

Which of the following is a physical change? A) wood burning B) corrosion of a copper pipe C) combustion of gasoline D) sublimation of dry ice (carbon dioxide) E) None of these

D) sublimation of dry ice (carbon dioxide) A physical change occurs when a substance remains the same substance after the change occurs. The sublimation of dry ice is a phase change which are all physical changes. The substance is carbon dioxide before and after sublimation, just in a different phase. CO2(s) → CO2(g)

Convert 10.0 inches to centimeters (1in = 2.54cm). Choose only ONE best answer. A) 0.254cm B) 0.039cm C) 3.9cm D) 6.8cm E) 25.4cm

E) 25.4cm

Convert 3.0 m2 to cm2. Choose only ONE best answer. A) 0.03 cm2 B) 30 cm2 C) 300 cm2 D) 3000 cm2 E) 30,000 cm2

E) 30,000 cm2

A solid plastic cube with 10cm edges has a mass of 400g. What would be the mass of a solid cube of the same plastic with 20cm edges? Choose only ONE best answer. A) 400g B) 600g C) 800g D) 1600g E) 3200g

E) 3200g

Convert 10 pounds to grams (1kg = 2.2lbs). (Treat 10 pounds as 1.0x101 pounds so that it has 2 sig figs.) Choose only ONE best answer. A) 0.22g B) 220g C) 4.5g D) 450g E) 4500g

E) 4500g