Isotopes and Ions
What is an Isotope? What is an Ion?
Isotopes have the same atomic number but a different atomic mass, due to a change in neutrons.
What does 1 mole equal?
6.022 x 1023 atoms/molecules
What does heat capacity measure? What are the units for specific heat capacity?
The quantity of heat (usually in joules) required to change the temperature of a given amount of the substance by 1 °C. Specific heat capacity is measured in J/g°C.
What is the percent mass of iron in the compound Fe2O3?
~70%
What is the chemical formula of Iodine heptafluoride?
IF7
What is the charge of an iron ion with 24 electrons?
Fe2+
How many grams are in 3.700 moles of Na2O?
230.0 g Na2O
How much heat must a 6.5 g of gallium absorb from your hand to raise its temperature from 15.0 °C to 30.0 °C? Specific heat capacity of gallium is 0.372 J/g°C. Use sig figs
36 J
What is the empirical formula if a compound consists of 21.2% N, 6.1% H, 24.2% S and 48.5 % O?
N2H8SO4
What is the name of S2F10 and what is the formula mass? (Round to the nearest thousands place)
Disulfur Decafloride, 254.11 g/mol
How many protons and neutrons does Ne-22 have?
10 protons, and 12 neutrons
How many grams are there in 3.4 x 1024 molecules of NH3?
96 grams
A 120 g sample of an unknown substance was heated from 25°C to 40°C. In the process, the substance absorbed 628 joules of energy. What is the specific heat of the substance?
0.35 J/g °C
Balance the equation
__ AgI + __ Na2S -----> ___ Ag2S + ___NaI
_2_ AgI + _1_ Na2S -----> _1_ Ag2S + _2_NaI
What is the name of the binary acid, H2S(aq)?
Hydrosulfuric Acid
Have many electrons does B3+ have?
2 electrons
How many molecules are in 48.0 grams of NaOH?
7.23 x 1023 molecules NaOH
The temperature of a sample of water increases from 20°C to 46.6°C as it absorbs 5650 joules of heat. What is the mass of the sample? (Specific heat of water is 1.0 cal/g °C)
212g
Balance the equation
___ PCI5 + ___H2O --->___ H3PO4 +___ HCl
__1_ PCI5 + _4_H2O --->_1_ H3PO4 +_5_ HCl
What is the name of Fe(NO3)3, and what type of compound is this?
Iron(III)nitrate, Ionic Compound
What ion has 56 protons and 54 electrons?
Ba2+
How many grams of lithium are there in 340.6 g of lithium sulfite?
Li2SO3 has 1.045 grams of Li.
The temperature of a sample of iron with a mass of 10.0 g changed from 50.4°C to 25.0°C with the release of 47 joules of heat. What is the specific heat of iron? Is this change endothermic or exothermic?
0.185 J/g° C (endothermic)
Determine the empirical and molecular formula for chrysotile asbestos. Chrysotile has the following percent composition: 28.03% Mg, 21.60% Si, 1.16% H, and 49.21% O. The molar mass for chrysotile is 520.8 g/mol. The molar mass for chrysotile is 520.8 g/mol.
Mg3Si2H3O8 (empirical formula), Mg6Si4H3O16 (molecular formula)
What is the name of the compound HC2H3O2 and what is the formula mass? (Round to the thousands place)
Acetic Acid, 60.05 g/mol