Chm 151 exam 1 ACTUAL UPDATED QUESTIONS AND CORRECT ANSWERS
, What are the three states of matter? Solids, liquids, and gases
What is a pure substance? An element or a compound
What is a homogeneous mixture? A mixture that has a uniform composition
What is a heterogeneous mixture? A mixture that does not have a uniform composition
What is the difference between physical and chemical Physical changes do not alter the substance's composition, while chemical
changes? changes do.
What are the rules for significant figures in Use the least number of decimal places.
addition/subtraction?
What are the rules for significant figures in Use the least number of significant figures.
multiplication/division?
What is the conversion factor for 1 cmr? 1 mL
How do you convert cm to ft? Start with the number of centimeters you are given. 1 foot equals 30.48
centimeters. Divide the number of centimeters by 30.48.
How do you convert m/s to km/hr? Start with the speed in meters per second. Multiply by a conversion factor to
change meters to kilometers (1 km / 1000 m). Then multiply by a conversion factor
to change seconds to hours (3600 s / 1 hr). Use remaining numbers for (km/hr).
How do you convert ns to ms? Start with the number of nanoseconds. 1 nanosecond = 1 × 10⁻⁹ seconds. 1
millisecond = 1 × 10⁻r seconds. Since milliseconds are larger than nanoseconds,
divide by 1 × 10⁶ (or move the decimal 6 places to the left). The answer you get is
the number of milliseconds.
How do you convert between squared or cubic units? Find the normal conversion between the units. If the units are squared, square the
conversion number. If the units are cubed, cube the conversion number. Multiply
and cancel units.
, What are the three states of matter? Solids, liquids, and gases
What is a pure substance? An element or a compound
What is a homogeneous mixture? A mixture that has a uniform composition
What is a heterogeneous mixture? A mixture that does not have a uniform composition
What is the difference between physical and chemical Physical changes do not alter the substance's composition, while chemical
changes? changes do.
What are the rules for significant figures in Use the least number of decimal places.
addition/subtraction?
What are the rules for significant figures in Use the least number of significant figures.
multiplication/division?
What is the conversion factor for 1 cmr? 1 mL
How do you convert cm to ft? Start with the number of centimeters you are given. 1 foot equals 30.48
centimeters. Divide the number of centimeters by 30.48.
How do you convert m/s to km/hr? Start with the speed in meters per second. Multiply by a conversion factor to
change meters to kilometers (1 km / 1000 m). Then multiply by a conversion factor
to change seconds to hours (3600 s / 1 hr). Use remaining numbers for (km/hr).
How do you convert ns to ms? Start with the number of nanoseconds. 1 nanosecond = 1 × 10⁻⁹ seconds. 1
millisecond = 1 × 10⁻r seconds. Since milliseconds are larger than nanoseconds,
divide by 1 × 10⁶ (or move the decimal 6 places to the left). The answer you get is
the number of milliseconds.
How do you convert between squared or cubic units? Find the normal conversion between the units. If the units are squared, square the
conversion number. If the units are cubed, cube the conversion number. Multiply
and cancel units.
