CHEM FINAL
A sample of Boron has a mass of 15.07 grams. Boron has three known isotopes B¹⁰ (19.9% abundance), B¹¹ (80.000125% abundance) and B⁸ (0.000875% abundance). Determine how much Boron 10 is present in the sample
1.67x E23
What is the concentration of 10 mL Hal needed to dilute 0.035L to a concentration of 0.500M HCl
1.75M
Calculate the enthalpy of the reaction: 2HNO₃(aq) + NO(g) → 3NO₂(g) + H₂O(I) NO₂(g)= -937.86. H₂O(I)= -970.30 HNO₃(aq)= -1645.22. NO(g)= -631.62
138.18
What is the molar mass of the following compound H₁₁C₉O₂N₁
165.174
What volume in mL, of concentrated hydrochloric acid (12.0M HCl), is needed to prepare 2.75L of a 0.750M solution?
172 mL
Which pf the following is the electron configuration for Polonium?
1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰5p⁶6s²4f¹⁴5d¹⁰6p⁴
Which set of quantum numbers is permitted by the rules of quantum mechanics? (n,I, mI, ms respectively)
2,1,0,1/2
What is the maximum mass (in grams) of NO that could be obtained from 3.25g of NH₃ and 3.50g O₂ ? NH₃ + O₂ → NO + H₂O
2.63 g
Neon has 2 major isotopes: Neon 20 and Neon 22. If 168 out of every 195 neon atoms are Neon 20 (199.2g/mol), what is the average mass of Neon?
20.26
A gas sample occupying a volume V at temperature T is heated to twice its initial temperature. What is its new volume?
2V
(NH₄)₃PO₄ + Pb(NO₃)₄ → Pb₃(PO₄) + 12NH₄NO₃ Balance the following equation and choose the correct coefficient for PB(NO₃)₄
3
How many electron domains are around the carbon? O=C-O-H |
3
How many significant figures will be in the answer to this 1.005+3.4655+8.9= ?
3
A Neon sign is emitting a blue light with a wavelength of 564 nm. What is the energy (in joules) emitted by this sign?
3.53 E-19
How many significant figures are in the number 0.008020?
4
How many electrons are in the following atom ¹⁰⁴Ag³+
44
How many neutrons are in the atom ¹⁰⁴Ag³+
57
What is the percent composition of Hydrogen in the molecule H₁₁C₉O₂N₁?
6.8%
Calculate the heat absorbed when 28g of water is heated from 23°C to 85°C (water Q=4.18 J/g°C)
7.256 kJ
Al(s) + HCl(aq) → AlCl₃(aq) + H₂(g) According to the reaction, how many grams of Aluminum are necessary to produce 0.5mol of Hydrogen gas (not balanced)
9.0
Given the following equation, 3Fe(NO₂)₂(aq) + 2Al(s) → 3Fe(s) + 2Al(NO₃)₃(aq) _______ is oxidized and ______ is reduced
Al, Fe
(NH4)3PO4
Ammonium Phosphate
BeF2
Beryllium fluoride
Which equation represents reduction?
BrO⁻ →Br₂
1.50g sample of hydrocarbon undergoes complete combustion to produce 4.40g of CO₂ and 2.70g of H₂O. What is the empirical formula of this compound?
CH₃
Which pair of atoms would make a covalent bond?
Carbon + Chlorine
Which isoelectronic series is correctly arranged in order of increasing radius? (smallest to largest)
Ca²+ < K+ < Ar < Cl-
[CoCl4]^+
Cobalt(V) Chloride
2Mg + O₂ → 2MgO is an example of a ______ reaction
Combination
Disulfram is a drug that contains 40.52% C, 6.799% H, 9.45% N, 43.17% S. If the molecular weight is 296.539 what is the molecular formula?
C₁₀H₂₀N₂S₄
Which molecule contains 5 sigma bonds an 1 pi bond?
C₂H₄
Caffeine, a stimulant found in coffee, tea, and certain soft drinks, contains C, H, O, and N. Combustion of 1.00 mg of caffeine produces 1.813mg CO₂, 0.4639mg H₂O, and 0.2885mg N₂. Find the empirical formula
C₄H₅N₂O
A carbohydrate is a compound composed solely of carbon, hydrogen, and oxygen. When 10.7695g of an unknown carbohydrate (MW=128.2080 g/mol) was subjected to combustion analysis with excess oxygen, it produced 29.5747g CO₂ and 12.1068g H₂O. What is the molecular formula?
C₈H₁₆O
What orbital is described by the following quantum number? n=4 I=2 mI=+1 mS=+1
D
An element's radius _______ as you go from left to right across the periodic table, and _______ as you go from bottom to top of the table
Decreases, Decreases
What intermolecular forces are exhibited by the following molecule? PH₃ (more than one can be circled)
Dispersion and Dipole-Dipole
As an electron moves from the ground state to the excited state, what is happening?
Electron absorbs energy
Which of the following is a halogen?
F
What orbital is being addressed; n=5 I=5 mi=+2 ms=+1/2
F orbital
What property of hydrogen is represented by the equation H(g) → H⁺(g) + e⁻
First ionization energy
Which of the following is a weak acid?
HF
Which of the following atoms is most likely to loose an electron when forming an ion?
K
Krypton monoxide tetrafluoride
KrOF4
Which molecule is incorrectly matched with its shape as predicted by VESPR?
NO₂⁻, linear
Which element has the second highest ionization energy?
Na
Which of these sets are not isoelectronic?
Na⁺, O²⁻, Ar , F⁻
Is XeO₆
Non-polar
When the molecules N₂, N₂O, and N₂O₄ are arranged in order of decreasing N-N bond length, which order is correct ?
N₂O₄, N₂O, N₂
A coffee cup without a lid is an example of which thermodynamic system?
Open system
Which of these compounds is not soluble?
PbCl₂
C3H8
Propane
Which of the following is not a chemical reaction?
Shredding paper
What is the hybridization of Sulfur SF₆?
Sp³d²
What is the molecular geometry of CIF₃?
T-shaped
Which statement is true about the most stable Lewis structure for HCN?
The central atom is sp hybridized
Copper from (5.00g Copper(II) metal reacts with a solution containing 20.0g of Silver Nitrate to form Silver solid and Copper Nitrate) is? Note: for clarity, copper will originally not share any electrons
The reducing agent
Cooking an egg endo or exo?
endothermic
Evaporating water endo or exo?
endothermic
Snow forming in storm clouds endo or exo?
exothermic
What is the molecular geometry of PH₃?
trigonal pyramidal
Choose the order that correctly ranks the energies of electromagnetic regions from shortest to longest wavelength
ultraviolet < infrared < microwave
Which of the following is a proper resonance structure for azide (N₃)?
*** Multiple all are correct ***
What are the signs of (q) and (w) respectively, when a system absorbs heat and does work on the surroundings?
+ , -
What is the formal charge of the central atom in PO₂³⁻
-1
From the following information, calculate the bond enthalpy of the reaction: CO(g) + H₂(g) → CH₃OH(g) (not balanced) _ O-O 146. C-O 358. C=O 799. C=O. O=O 495 O-H 463. C-H 413 H-H 436 KJ/mol units
-116
Which of the following is equal to 116 degrees kelvin?
-250.87 °F
5.00g Copper(II) metal reacts with a solution containing 20.0g of Silver Nitrate to form Silver solid and Copper Nitrate. How much Copper Nitrate is created in moles?
0.0589
What is the molarity of Potassium in a solution prepared by diluting 300mL of 0.47M K₂CO₃ to 1.00L?
0.282M
A reaction produced 36.0g of O₂ gas at 10°C in a sealed vessel with a measured volume of 35.0L What is the pressure in atmospheres?
0.745atm
A reaction mixture is prepared containing 0.60 mol of aluminum and 1.20mol of manganese dioxide. The mixture is heated until one of the reactants has been completely consumed according to the equation: 2Al +3MnO₂ → 3Mn + Al₂O₃ how much manganese can be produced?
0.90 mol