Chemical Equations
A piece of magnesium metal is placed in a solution of hydrochloric acid, resulting in the formation of hydrogen gas and a solution of magnesium chloride. What type of reaction is this?
single-displacement
When mixed, solutions of copper(II) nitrate, Cu(NO3)2, and sodium phosphate, Na3PO4, will form a precipitate of copper phosphate, Cu3(PO4). The balanced equation is:
3Cu(NO3)2(aq) + 2Na3PO4(aq) → Cu3(PO4)2(s) + 6NaNO3(aq)
If 10 mols of Na3PO4 are used, how many mols of Cu3(PO4)2 are made?
5 mols
The following reaction absorbs 393 kJ of heat for each mole of CO2 that reacts. CO2(g) → C(s) + O2(g). Is this reaction endo or exothermic, and is the value of q positive or negative?
endothermic with a positive q
How many valence electrons are in Bromine?
7
What is the Lewis Structure for O2-?
board!!
True or False: Na2SO4 is insoluble in water.
False
Nitrogen monoxide reacts with oxygen according to the following reaction:
2NO(g) + O2(g) → 2NO2(g)
If 12 moles of nitrogen monoxide are combined with 10 moles of oxygen, how many moles of NO2 should form?
12 mol NO2
Rank the following types of electromagnetic radiation from shortest wavelength to longest wavelength: visible, ultraviolet, microwave, infrared, x-ray.
x-ray < ultraviolet < visible < infrared < microwave
Which element has the abbreviated ground-state electron configuration [Ne]3s23p2?
Si
Which of the following contains polar covalent bonds?
A) O2
B) MgCl2
C) KBr
D) NO2
E) None of these
NO2
Balance the equation:
P4+Cl2-->PCl3
P4+6Cl2--> 4PCl3
Iron ore can be converted to pure iron according to the equation Fe3O4(s) + 4CO(g) → 3Fe(s) + 4CO2(g). How many moles of pure iron can be produced from the reaction of 1.25 moles of iron ore?
3.75 mol Fe
What is the heat change when a 225 g sample of olive oil [Colive oil = 1.79 J/(g°C)] is cooled from 95.8°C to 52.1°C?
-17600 J or -1.76x104 J
Which ion is expected to be the largest?
A) Ca2+
B) S2−
C) Cl−
D) K+
E) All these ions are the same size.
S2-
The correctly drawn Lewis Structure for CBr4 will have how many bonds and lone pairs?
4 single bonds, 12 lone pairs
When powdered sulfur, S8, burns in air, a purple flame is produced, as well as a toxic, foul-smelling gas. What is the balanced equation for the reaction between sulfur and oxygen gas?
S8(s)+8O2(g)-->8SO2(g)
Consider the reaction between hydrogen and oxygen gases to form water: 2H2(g) + O2(g) → 2H2O(l) If 8.5 moles of oxygen react with sufficient hydrogen, how many grams of water should form?
310 g
) The wavelength of the blue light given off by a mercury vapor street lamp is 436 nm. What is the frequency of this light in hertz (s–1)?
6.88 × 1014
What is the correct ground state electron configuration for a phosphorus atom?
1s22s22p63s23p3
) Which of these molecules or ions has a violation of the octet rule (other than H)?
A) H2S B) SF4 C) CH4 D) CO2 E) PCl3
SF4
Given the following chemical equation, write the net ionic equation:
Na2CO3(aq)+Ba(NO3)2(aq) --> 2NaNO3(aq)+BaCO3(s)
CO32- + Ba2+-->BaCO3(s)
What mass (in grams) of SF6 should be produced by the following reaction if 7.00 g of sulfur is mixed with 9.00 g of fluorine? S + 3F2 → SF6
11.5g SF6
Which of the following electron transitions in the hydrogen atom result in emission of light with the longest wavelength?
A) n = 2 to n = 3
B) n = 2 to n = 6
C) n = 6 to n = 2
D) n = 3 to n = 2
E) All of these emit light with the same wavelength.
n=3 to n=2
Rank the following elements in order of increasing ionization energy: Sr, He, Si, F
Sr < Si <F < H
Draw the Lewis Structure for BF3
on board!