PA Questions
Which base unit pairing is correct for a nanoliter?
1 nL = 10 -9 L
The speed of light in a vacuum is often rounded to 300,000 km/s. What is the time required for light to travel 1,500,000 km?
5 s.
What is 0.00054 converted to scientific notation?
5.4 × 10 -4
The concentration of a reactant in a chemical reaction is measured for 0.40 seconds. What is the correct value for the rate of change of concentration of the reactant?
-0.50 M/s
What is the value for the slope of the line in the graph below?
-2°C/s
Given: (°C × 9/5 + 32 = °F) What is -40°C converted into degrees Fahrenheit?
-40°F
Given: (°C × 9/5 + 32 = °F) What is -20.°C converted into degrees Fahrenheit?
-4°F
Given a graph of concentration versus time: What is the magnitude of the change in concentration (M) in the first three minutes?
1.5
What is the measurement of the length of the side of the density cube?
1.60 cm
A healthy adult male needs around 2,500. kcal a day to maintain his weight (1 kcal = 4.184 kJ). How many kilojoules is this per day?
10,460 kJ
An element has two isotopes. Given the table: Isotope Atomic Mass (amu) Percent Abundance A 10.01 19.9% B 11.00 80.1% What is the average atomic mass of this element?
10.80 amu
Given the measurements: 10 nm 100 m 200 μm What is the correct order from largest to smallest?
100 m, 200 µm, 10 nm
What is the solution of the mathematical expression, with the correct number of significant figures? 12.1 + 0.79 + 91.0 + 14.212 = ____
118.1
A gas station dispensed 50. L of gas to a customer (1 gal = 3.8 L). How many gallons of gas did this customer receive?
13 gal
How many neutrons are present in magnesium-26 ( 26Mg)?
14 neutrons
What is the solution of the mathematical expression, with the correct number of significant figures? (2.6 × 15.2 × 9.4) / 25.45 = ____
15
What is the volume of liquid shown in the graduated cylinder to the appropriate degree of uncertainty?
16.5 mL
Given the image of a weight measurement: What is the correct measurement to the appropriate number of significant figures?
163.640 g
A reaction is predicted to produce 32.4 g of a compound. When the product is measured, there are only 26.1 g made experimentally. What is the percent error for this reaction?
19.4%
Given the following numbers in scientific notation: 1) 9.990 × 10 5 2) 1.001 × 10 -5 3) 9.99 × 10 6 4) 1.00 × 10 5 What is the correct sequence from smallest to largest?
2, 4, 1, 3
Boron has two isotopes: 10B with a mass of 10.01 amu, and 11B with a mass of 11.01 amu. The average atomic mass of boron is 10.81 amu. What is the relative percentage abundance of the boron isotopes?
20% 10B and 80% 11B
The speed of sound in dry, ambient air at sea level is 343 m/s. How many meters will a sound wave travel in 60.0s?
20,600 m
Given the following numbers in scientific notation: 1) 2.70 × 10 2 2) 2.70 × 10 -2 3) 1.02 × 10 20 4) 4.56 × 10 -30 What is the correct sequence from largest to smallest?
3, 1, 2, 4
Given the calories recorded in a 1 oz serving of 10 breakfast bars: 55, 54, 59, 55, 52, 51, 57, 49, 61, 57 What is the standard deviation of the data set?
3.7
What is 0.003721 converted to scientific notation?
3.721 × 10 -3
What is the value of the following expression in correct significant figures? 1.8 × 20.5 × 10.00
370
What is the length of the line to the correct number of significant figures?
370 cm
A city's official high temperatures for the first week in February are shown below. Day Temperature (°F) 1 30 2 38 3 36 4 20 5 24 6 33 7 38 What temperature is the mode for these seven days?
38
Aluminum reacts with chlorine gas to yield aluminum chloride. Given the data: Theoretical yield: 58.3 g Measured yield: 35.2 g What is the percent error of the reaction?
39.6%
What is the atomic number for carbon-14 ( 14C)?
6
A team wins 12 of 20 games per season on average. What is the probability of the team winning the next game?
60%
On average, a city's temperature is below the freezing point for 21 of 31 days in January. What is the probability of the temperature being below freezing in January?
68%
What is the correct order when 70 cg, 7 mg, and 700 kg are listed from smallest to largest mass?
7 mg, 70 cg, 700 kg
A runner races the half marathon with a speed of 3.5 m/s (1 m/s = 2.2 mph). How many miles per hour is this?
7.7 mph
How many electrons are present in oxygen-17 ( 17O)?
8 electrons
A certain unknown element "A" has three common isotopes. Given the table of the relative abundances of these isotopes and their exact masses: Isotope Relative Abundance Exact Mass 86A 9.86% 85.91 amu 87A 7.56% 86.91 amu 88A 82.58% 87.91 amu What is the average atomic mass of element A?
87.64 amu
Which situation is associated with kinetic energy?
A child is crawling across a room.
The formula for a solution of hydrofluoric acid is HF (aq). Which type of substance is represented by this formula?
A homogeneous mixture
Which situation demonstrates kinetic energy?
A soccer ball kicked toward the goal
A student measures the volume of an object five times. What correctly describes the accuracy and precision of these measurements if the true value is 50.00 mL?
Accurate but not precise
When the pendulum is in motion, which point in its swing does the pendulum have the greatest potential energy?
At the turning point
Which change is an example of a chemical change?
Bicycles rusting
What is the name of the compound with the formula CO?
Carbon monoxide
Which atom does this represent?
Carbon-10
Which property is a physical property?
Color
What is the name of the compound with the formula N 2O?
Dinitrogen monoxide
Which type of chemical bond forms between nitrogen and oxygen?
Covalent bond
A farmer conducts an experiment to study the effect of sunlight on lettuce and turnip growth. For one month, the farmer keeps the lettuce in sunlight and the turnips in the shade. The farmer makes daily measurements of the mass of each vegetable. Which modification should the farmer make to improve the validity of the results?
Expose both vegetables to a controlled amount of shade and sunlight
Given the graph of the relationship between the mass and volume of an unknown liquid as it is exposed to room temperature: What is an appropriate title for this graph?
Mass versus volume of an unknown liquid
Which species has 12 protons and 10 electrons?
Mg 2+
N 2 and O 2 are abundant in the earth's atmosphere. Which type of substances are N 2 and O 2?
Molecules
Which option ranks the objects from largest to smallest?
Pancreas, red blood cell, water molecule, atom
Which property of matter includes heat capacity, density, melting point, and boiling point?
Physical
A group of students sets up an experiment using two groups of plants of the same variety. Three plants each were planted in two identical containers that received 18 hrs. of sunlight and 1 tsp of water each day. The plants in one group were given fertilizer dissolved in the water every 5 days. The heights of the plants in both groups were recorded at the beginning of the experiment and again 4 wks. later. The data showed that the plants given the fertilizer grew faster than those that did not receive any fertilizer. Which modification to the experimental design will improve the validity of the experiment?
Plant 20 plants in each of the containers instead of 3 plants
Which pair of elements will form an ionic bond?
Sodium and chlorine
A substance has a definite shape and definite volume. What is the physical state of the substance?
Solid
A student puts 100 g of liquid water in a freezer and measures its mass after it is frozen. Which scenario is consistent with the law of conservation of mass?
The mass of the ice is still exactly 100 g.
Which event demonstrates a physical change?
The soil along a river is eroded by deer.
Which statement describes the law of conservation of matter? When energy is added to a given amount of matter, there is an increase in the total amount of matter present. When energy is removed from a given amount of matter, there is a decrease in the total amount of matter present. When matter is converted from one substance to another, there is no change in the total amount of matter present. When matter is converted from one physical state to another, there is a reduction in the total amount of matter present.
When matter is converted from one substance to another, there is no change in the total amount of matter present.
Which unit correctly represents the width of a door?
m