midterm Flashcards
(73 cards)
What is the difference between quantitative and qualitative measurements?
Quantitative - measurement without units and numbers; Qualitative - measurement with units and numbers
Example: 10°C is quantitative, while ‘warm’ is qualitative.
Define accuracy in measurement.
How well the measurement is to the exact, known value.
Define precision in measurement.
Repeated similar measurements not necessarily exact.
List the base units for length, mass, and temperature.
- Length - Meter (m)
- Mass - Kilograms (kg)
- Temperature - Kelvin (K)
What is the volume formula for a rectangular object?
V = length x width x height.
What is the density of water?
1 cm³ = 1 mL.
What is scientific notation used for?
To express large or small numbers in a compact form.
Fill in the blank: Water displacement can be calculated using Δ = ______.
final V - initial V.
What are the rules for significant figures?
- All non-zero digits are significant.
- Zeros between non-zero digits are significant.
- Leading zeros are not significant.
- Trailing zeros are significant only if there is a decimal point.
What is the formula for percent error?
% error = |(measured value - accepted value) / accepted value| x 100.
What is a mole (mol)?
Amount of a substance.
At standard temperature and pressure (STP), what volume does 1 mole of gas occupy?
22.4 Liters.
Define element.
A substance that cannot be decomposed into simpler substances by chemical means.
What is a compound?
A substance composed of 2 or more different elements chemically combined.
What is a mixture?
Two or more substances physically combined.
Differentiate between homogeneous and heterogeneous mixtures.
- Homogeneous mixture = solution = same throughout.
- Heterogeneous mixture = not the same throughout.
What are the three phases of matter?
- Solid (s)
- Liquid (l)
- Gas (g)
What is potential energy?
Stored energy, such as chemical energy in bonds.
What does the term ‘endothermic’ refer to?
Energy is being absorbed.
What is the formula for specific heat capacity?
Q = mCΔT.
What does the first law of thermodynamics state?
Matter and energy are neither created nor destroyed, only transferred.
What is Boyle’s law?
As the pressure on a confined gas increases, the volume decreases (P ↑ V ↓).
What is Charles’ law?
The volume of a gas at constant pressure is directly proportional to its Kelvin temperature (T ↑ V ↑).
What is the Ideal Gas Law?
PV = nRT.