Concepts
Saltwater is an example of this type of mixture because it looks the same throughout
homogeneous mixture (solution)
How many significant Figures are in 1800000
2
Convert 3°K to F.
- (TF − 32) ÷ 1.8 = TC ; (𝑇𝐶× 1.8) + 32 = 𝑇𝐹 ; 𝑇K = 𝑇C + 273.15
-454°F
What does "X" represent in the following symbol?
8035X
Br
Select the compound that is covalent (molecular).
A) Li₂O
B) MgCl₂
C) CO₂
D) KBr
E) CaO
CO2
_______ are pure substances that consist of only one type of atom, while _____ are pure substances that consist of 2 or more elements chemically bonded
Elements ; Compounds
How many nm are in 7.2km?
7.2 * 1012 nm
Determine the density of an object that has a mass of 149.8 g and displaces 12.1 mL of water when placed in a graduated cylinder.
12.4 g/mL
How many protons, electrons, and neutrons are present in an atom of Cl-37
Protons: 17
Electrons: 17
Neutrons: 20
Calculate the mass percent composition of sulfur in Al2(SO4)3.
28.1%
Which of the following statements is FALSE according to Dalton's Atomic Theory?
A) Atoms combine in simple whole-number ratios to form compounds.
B) All atoms of chlorine have identical properties that distinguish them from other elements.
C) One carbon atom will combine with one oxygen atom to form a molecule of carbon monoxide.
D) Atoms of sodium do not change into another element during a chemical reaction with chlorine.
E) An atom of nitrogen can be broken down into smaller particles that will still have the unique.
E) An atom of nitrogen can be broken down into smaller particles that will still have the unique.
Solve this problem, ensuring you are rounding to the proper number of Significant Figures.
(15.02−14.8) ÷ (0.0320×1.5)
5
What is the mass 23.0 mL sample of Aluminum with a density of 2.70 g/mL?
62.1g
. What species is represented by the following information (element and charge)?
p+ = 47 n° = 62 e− = 46
Ag+
How many molecules of CO₂ are in 44.0 g CO₂? The molar mass of CO₂ is 44.01 g/mol.
6.02 * 1023 molecules
A student repeatedly measures the mass of a sample and gets 5.01 g, 5.01 g, and 5.02 g. However, the true mass is 5.50 g. This data set is best described as this (think about precision and accuracy).
precise, but not accurate
A car is traveling at a speed of 55.0 miles per hour. What is its speed in kilometers per minute?
1 mile=1.609 km
1 hour=60.0 min
1.47 km/min
A sample of aluminum has a mass of 54.0 g. The density of aluminum is 2.70 g/mL.
What is the volume of the aluminum sample in mL?
20.0 mL
Calculate the atomic mass of chlorine, given that naturally occurring chlorine consists of:
35.45 g/mol
The molecular mass of Benzene, an important industrial solvent, is 78 g/mol and its empirical formula is CH. What is the molecular formula of Benzene?
C6H6
When two elements form two different compounds, the masses of element B that combine with 1 g of element A can be expressed as a ratio of small whole numbers. Which law or theory does this refer to?
Law of Multiple Proportions
Veterinarians sometimes use troy units when measuring small quantities of medication. A particular dose of a medication has a mass of 7.5 grains.
Express this mass in kilograms, given the following conversions:
24 grains (gr) = 1 pennyweight (dwt)
20 pennyweight = 1 troy ounce (oz t)
1 troy ounce = 31.103 grams
1 kilogram (kg) = 1000 grams (g)
4.9 * 10-4kg
A mass of aluminum occupies 2.50 L. What volume would an equal mass of water occupy? The density of aluminum is 2.70 g/mL and the density of water is 1.00 g/mL.
6750 mL or 6.75L
An element exists naturally as two isotopes. Isotope A has an isotopic mass of 62.93 amu and makes up 69.20% of the element's natural abundance. The element has an average atomic mass of 63.55 amu. What is isotopic mass of isotope B?
64.94 amu
Freons are gaseous compounds used in refrigeration. A particular freon consists of 9.93% carbon, 58.6% Chlorine, and 31.4% Fluorine by mass. What this freons empirical formula?
CCl2F2