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# Chemistry Quiz #2

Chemistry Chapters 4, 5, and 6
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What are the subatomic particles of a proton?
A proton has a mass (kg) of 1.67262 x 10^-27 a mass (AMU) of 1.0073 and a 1+ charge.
What are the subatomic particles of a neutron?
A neutron has a mass (kg.) of 1.67493 x 10^-27 and a mass (AMU) of 1.0087 and a 0 charge.
What are the subatomic particles of an electron?
An electron has a mass (kg.) of 0.00091 x 10^-27 and a mass (amu) 0.00055 and a 1- charge.
What is the mass ratio of sodium to fluorine in sodium fluoride is 1.21:1. A sample of sodium fluoride produced is 37.5 g. of sodium upon decomposition. How much fluorine in grams was formed?
37.5 g Na./ 1gf/1.21 g Na = 30.9917 3 sig figs. round to 31.0
Mg3(PO4)2 Determine the number of each type of atom in each of the following formulas?
NMg 3, Np 2, No 8
Write a formula for the compound that forms from calcium and phosphate. Express your answer as a chemical formula.
Ca3(PO4)2
Spell out the full name of the compound CrCl2
chromium (II) chloride
Gallium has two naturally occurring isotopes: Ga-69 with mass 68.9256 amu and a natural abundance of 60.11%, and Ga-71 with mass of 70.9247 amu and a natural abundance of 39.89%. Calculate the atomic mass of gallium.
Steps: Convert the percent natural abundances into decimal form by dividing by 100. Fraction Ga-69= 60.11/100=0.6011
Fraction Ga-71=39.89/100=0.3989.
Step: 2 Use the fractional abdundances and the atomic masses of the isotope to compute the atomic mass.
Atomic mass =(0.6011 x 68.9256 amu) + (0.3989 x 70.9247) = 41.4321 amu + 28.2919 amu = 69.7231 You need four significant figures 69.72 amu
Sulfuric Acid
H2SO4
What is an isotope?
An isotope is an atom with same number of protons but different number of neutrons are called isotopes.
Chromate
CrO42
Hydrochloric acid
HCI
Phosphoric acid
H3PO4
Perchloric acid
HCIO4
Ammonium
NH4+
Phosphate
PO43-
Hydroiodic acid
HI
Hydrobromic acid
HBr
Nitric acid
HNO3
What is an ion?
An ion is an atom (or group) of atoms that has gained or lost one or more electrons, so that is has an electric charge (+).
Determine the number of protons in 266 and number of neutrons 88 RA
The number of protons is 88 and the number of neutrons is 178. To total 266 top number. 88+178=266
Calculate the mass of aluminum in grams of 6.73 moles of aluminum?
Given: 6.73 mol Al. Find: g Al 26.98/1 mol Al 26.98 = 1 mol. Al from the periodic table 6.73 mol Al. x 26.98/1 mol Al =182 g Al.
What is a chemical formula?
A chemical formula is the composition of a molecule.
What is an empirical formula?
A chemical form is the simplest whole number ratio of atoms.
What is a molecular formula?
A molecular formula is the actual number of atoms of each element.
What are ionic compounds?
Ionic compounds contain 1 or more cations paired with one or more anions.