Isotopes are atoms with identical atomic numbers but different mass numbers.
100
Identify the type of reaction for each of the chemical equations below. (combustion, combination, decomposition, single replacement, double replacement)
a) Ni(s) + 2AgNO3(aq) → 2Ag(s) + Ni(NO3)2(aq)
b) P4(s) + 10F2(g) → 4PF5(g)
c) H2CO3(aq) → H2O(l) + CO2(g)
d) C6H12O6(aq) + 6O2(g) → 6CO2(g) + 6H2O(l)
a) Single replacement
b) Combination
c) Decomposition
d) Combustion
100
Consider the reaction below. When a 45.00 gram sample of ethanol is burned with excess oxygen, about how much energy is released as heat?
C2H5OH(l) + 3 O2(g) --> 2 CO2(g)+ 3 H2O(l)
∆H = -1.40 × 10^3 kJ
1.40 × 10^3kJ
100
What is meant by effective nuclear charge? How does the effective nuclear charge experienced by valence electrons of an atom vary going from left to right across a period of the periodic table?
effective nuclear charge is a representation of of the average electrical field experienced by a single electron.
It increases.
100
Predict the ordering of C-O bond lengths in CO, CO2, and CO32-
CO>CO2>CO32-
200
Which of these compounds would you expect to be covalent:
N2O Na2O SF4 CaCl2 P2O5 PbF2 CCl4
N2O SF4 P2O5 CCL4
200
Which of the following ions will always be a spectator ion in a precipitation reaction?
a) Cl-
b) NO3-
c) NH4+
d) S2-
e) SO4-
Ionic compounds containing NO3- and NH4+ are always soluble so they will always be spectators
200
From the heats of formation
H2(g) + F2(g) --> 2 HF(g) ∆H = -537 kJ
C(s) + 2 F2(g) --> CF4(g) ∆H = -680 kJ
2 C(s) + 2 H2(g) --> C2H4(g) ∆H = +52.3 kJ
Calculate ∆H for the reaction of ethylene with F2:
C2H4(g) + 6 F2(g) --> 2 CF4(g) + 4 HF(g)
-2.49 × 10^3 kJ
200
Arrange the following sets of atoms in order of increasing size
a) Se2- Te2- Se
b)Co3+ Fe3+ Fe2+
c)Ca Ti4+ Sc3+
Se Se2- Te2-
Co3+ Fe3+ Fe2+
Ti4+ Sc3+ Ca
200
Which of the following atoms is the most electronegative in each set?
(a) Na, Mg, K, Ca
(b)P, S, As, Se
(c)Be, B, C, Si
(d) Zn, Ge, Ga, As
(a)Mg (b)S (c)C (d)As
300
Indium reacts with bromine to form InBr3. In the balanced equation for this reaction, the coefficient of the indium (III) bromide is
2
300
What Mass of KCL is needed to precipitate the silver ions from 15.0 mL of 0.200 M AgNO3 solution?
0.227 g KCl
300
Write the electron configuration for Ca, Fe, Zr, Br
What is the difference between the electron-domain geometry and the molecular geometry of a molecule?
Electron domain geometry looks at all electron domains (bonding and nonbonding electrons),
Molecular geometry just describes positions of the atoms.
300
What is the difference between ionic and covalent bonds? Why are they different?
In covalent bonds atoms share electrons, in an ionic bond one atom gives up electrons and the other accepts electrons.
The reason these types of bonds are different is because of the differences in electronegativities of the atoms in the bonds. The atoms in a ionic bond have bigger differences in electronegativity than the atoms in a covalent bond
400
Naming the following compounds
SF4, CaCl2,PbSO4, N2O5, FeCl3, NaNO3
What does it mean when I say that enthalpy is a state function and an extensive property?
Enthalpy is a state function because the change in enthalpy going from the reactants to the products in a reaction is the same no matter what steps were taken in the reaction.
Enthalpy is an extensive property because the amount of heat absorbed or released by a reaction depends on the amount of substance we are using.
400
What does Hund’s rule and Pauli exclusion principle described.
Hund’s rule says that all orbitals in a subshell are filled with 1 electron before any of the others receive a second.
Pauli exculusion principle states that no two electrons in an atom can have the same set of four quantum numbers.
400
Which periodic trend influences the lattice energy in ionic bonding?
Atomic radii
400
Which of the following has more than one unshared pair of valence electrons on the central atom?
(a)BrF5
(b)NF3
(c)IF7
(d)ClF3
(e)CF4
(d) ClF3
500
An unknown compound contains the elements C, H, and O. It is known to contain 48% C and 4.0% H by mass. The molar mass of this compound has been determined in the lab to have a value of 200. The molecular formula for this compound is
C8H8O6
500
Ask the Class a question related to the chemistry we have learned in class if no one can answer it then you get the points.
?
500
Atoms of an element Y have the ground state electronic configuration 1s22s22p63s23p1
When element Y forms a compound with Oxygen, what will the chemical formula be?
Y2O3
500
Ask the Class a question related to the chemistry we have learned in class if no one can answer it then you get the points.
?
500
The molecules and ions below include all of the following geometries except;
SiCl4 BrF- C2H2 TeF6 NO3-
(a) square planar
(b) tetrahedral
(c)octahedral
(d) trigonal pyramidal
(e) linear