Watered Down
What is the molarity of a solution that has 5.00 moles of solute and 2.05 liters of solution?
2.44 M
Which has the largest atomic radius: K, Ca, or Br?
K > Ca > Br
Identify the reaction type: 2H₂ + O₂ → 2H₂O
Combination (synthesis)
Describe what happens during beta decay.
A neutron converts into a proton and a high-speed electron is released.
How many molecules of CO2 are in 0.25 moles of CO₂?
1.5×1023 molecules CO₂
How many moles of solute are in 8.5 L of a 0.55 M solution?
4.68 moles
Which group contains the most electronegative elements?
Group 17 (Halogens) contains the most electronegative elements.
Balance and name the type of reaction:
___ Al + ___ Cl₂ → ___ AlCl₃
2 Al + 3 Cl₂ → 2 AlCl₃
Combination (synthesis)
A 64 g sample with a half-life of 2 hours is reduced to 8 g. How long has it decayed?
6 hours
Write a conversion map that solves for grams of products if given grams of reactants.
grams R --> moles R --> moles P --> grams P
What would the molarity of a solution be if you took 3.8 L of 2.3 M NaOH and added enough water to make the total volume 13.9L?
0.63 M
Define ionization energy and explain its trend across a period.
Ionization energy is the energy needed to remove the outermost electron from an atom.
It increases across a period because atoms have a smaller radius, so electrons are closer to the nucleus and more strongly attracted.
What evidence indicates a chemical reaction has occurred? (Give two)
Gas production
Precipitation formation
Light or heat production
Temperature change
How does gamma radiation change the atomic and mass numbers?
No effect because particles are not emitted
How many grams of sodium oxide are produced from 0.500 mol of Na using the reaction:
4Na + O₂ → 2Na2O?
15.5 g Na2O
34.8 g of Na2O are used to form a solution with a volume of 0.50 L. What is the molarity?
1.12 M
What causes atomic radius to increase down a group?
Atomic radius increases down a group because each element has more electron shells than the one above it.
What type of compound forms between ammonium and sulfate ions? Write the formula.
Ionic compound -- (NH4)2SO4
Write the nuclear equation for the beta decay of carbon-14.
146C --> 147C + 0-1e
C3H8+5O2→3CO2+4H2O
How many grams of water are produced when 44.0 g of C3H8 combust?
72.1 g H2O
2.5 L of a concentration solution of 1.5 M NaOH was diluted to 0.45 M. How much water was added to the concentrated solution?
5.8 L
Rank Na, Al, Cl, and Si in order of increasing electron affinity.
Na < Al < Si < Cl
Write the balanced equation for the complete combustion of CH₄.
CH4 + 2O2 → CO2 + 2H2O
Write the nuclear equation for the alpha decay of uranium-238.
²³⁸₉₂U → ²³⁴₉₀Th + ⁴₂He
C3H8+5O2→3CO2+4H2O
How many molecules of CO2 are produced from 0.250 moles of C3H8?
4.515×1023 molecules CO2