Quimica Inorganica Spellbook Flashcards
What type of bond is found in carbon monoxide?
A) Nonpolar single bond
B) Polar single bond
C) Polar double bond
D) Polar triple bond
(D) The Lewis Dot Structure for carbon monoxide has a triple bond that is polar, with the oxygen being slightly negative due to its higher electronegativity.
The Ksp value for silver iodide, AgI, is 4 x 10-16. What is the molar solubilitry of silver iodide?
A) 2 x 10-8
B) 2 x 10-16
C) 8 x 10-16
D) 8 x 10-32
(A) Because the concentrations of silver and iodide ions are equal, the expression to be solved is 4 x 10-16 = x2 where x = 2 x 10-8
If a sample of gas is heated from 10°C to 20°C, the volume of the gas will:
A) increase slightly from the original volume
B) be double the original volume
C) decrease slightly from the original volume
D) be half of the original volume
(A) In order to qualitatively determine the effects of temperature on a gas, the temperature must be in Kelvin, so the change in temperature is from 283 K to 293 K, or about 3%.
Which of these elements have the highest electronegativity?
A) Sodium
B) Silicon
C) Sulfur
D) Selenium
(C) High electronegativities are features of nonmetallic elements, with the highest electronegativity value assigned to fluorine.
What type of reaction is taking place in the precipitate formations?
A) Hydrolysis reaction
B) Single replacement reaction
C) Synthesis reaction
D) Double replacement reaction
(D) Each precipitate reaction is a double replacement (or double displacement) reaction.
The solubility product constant for silver chloride is 4 x 10-10. What is the solubility of silver chloride in a solution of 0.1 M NaCl?
A) 2 x 10-5
B) 4 x 10-5
C) 4 x 10-9
D) 4 x 10-11
(C) This is an applicaiton of the common ion effect. Because the concentration of the Cl- ion is 0.1 M, the addition of a very small amount of the Cl- ion from AgCl is small enough to be ignored, so 4 x 10-10 = 0.1x where x is going to be equal to 4 x 10-9 M.
Ice at zero degrees Celsius is palced in water at zero degrees Celsius. Which of the following would occur?
A) The ice melts
B) All of the ice melts but part of the water also freezes
C) None of the ice melts and none of the water freezes
D) Some of the ice melts and some of the water freezes
(C) If the temperature is the same, no heat flow.
Pure bromine has a density of 3.2 g/cm3 at room temperature. What is the molarity of pure bromine?
20.0 M. At room temperature, there are (3.2 g/cm3 x 1000 cm3/L) 3200 g of bromine and so dividing it by 160 (Br2 = 80 + 80 = 160) would make a molarity of 20.0 M.
When 20.0 mL of a 0.1 M solution of potassium hypochlorite is added to 10.0 mL of a solution of 0.1 M solution of hypochlorous acid with a few drops of phenol red added to it, what color change, if any, would be observed?
(Hint: Phenol Red is yellow in acidic conditions and red in basic conditions)
Adding the basic salt KClO to a weak acid would increase the pH enough for it to become basic. So it would turn from yellow to red.
The equation below is unbalanced:
ClO3-1 + Mn+2 -> Cl2 + MnO4-1
What happens to the chlorine atoms in the process of the equation?
Chlorine atoms are reduced and each chlorine atom gains 5 electrons.
Oxidation Number of chlorine in the reactants: x - 6 = -1
x = 5
Oxidation Number of chlroine in the products: x = 0
x = 0
Consider the following excerpt from a reaction:
H2SO4(aq) -> 2CO2
What volume of 4.0 M sulfuric acid is needed to produce 44.8 L of carbon dioxide gas at STP?
250 mL. To have a 4.0 M concentration, sulfuric acid needs to have 1 mole / 0.25 L. Seeing as one mole would create 2 moles of carbon dioxide (which is 44.8 L at STP), we need 250 mL of sulfuric acid.
The heat of combustion of tristerain (molar mass = 926) is 37,000 kj/mole. By how many degrees Celsius could 1000 grams of water be heated using the heat produced by the combustion of one gram of tristearin? The specific heat capacity of water is 4.181 J/g ºC
The temperature change of water could be found using ΔH = mCΔT. 37,000 J = (926 g)(4.184 J/gºC)(ΔT)
ΔT = 9.5 degrees.
The compound arsenic trichloride obeys the octet rule. What is the molecular geometry and polarity of phosphorous trichloride?
It is trigonal pyramidal in shape and it is polar.
Which of the following pairs of 0.1 M solutions will produce a precipitate?
A) Silver nitrate and lead(II) chloride
B) Lead(II) nitrate and nitric acid
C) sodium bromide and calcium chloride
D) potassium nitrate and mercury(II) acetate
Silver chloride is an insoluble solid. So: (A)
Given the equilibrium constants for the synthesis of hydrogen iodide (10-1) and hydrogen chloride (1016), the rate of synthesis of HCl compared to the rate of formation of HI at the same temperature is:
Reaction rates cannot be determined from equilibrium constants or other thermodynamic data.
Compared to aqueous HCl, the acidity of aqueous HI is:
HI is a stronger acid because I- ions are larger than Cl- ions, making HI bonds weaker than HCl bonds so HI more readily dissociates.
When the boiling points of the silver nitrate [AgNO3] and lead nitrate [Pb(NO3)2] solutions are compared, what results are obtained if both solutions are 0.1 M?
Boiling point elevation depends on the number of moles dissolved particles. Because the comparison is between equimolar solutions of lead nitrate and silver nitrate and because lead nitrate dissociates into three ions while silver nitrate dissociates into two ions, lead nitrate will have a higher boiling point.
When a piece of magnesium metal is placed in a solution of copper(II) nitrate, what occurs?
Because magnesium is more reactive than copper, the magneisum metal will be oxidized to magnesium ion and the copper ion is reduced to copper metal.
When lead (II) reacts with sulfuric acid, what is the most likely aqueous product?
PbSO4 because SO4 has a -2 charge and Pb has a +2 charge.
What prediction can be made about the miscibility of hexane and toluene?
Hexane and toluene will be miscible in each other because they can have London dispersion forces to facilitate mixing. Both are nonpolar, which rules out hydrogen bonding and dipole interactions.
Sulfur atoms can sometimes form compouns with more than four pairs of bonding electrons. Which orbitals are responsible for allowing sulfur atoms to do this?
A) 2p
B) 2d
C) 3d
D) 3p
(C) Expanded octets involve d orbitals. The second energy level has no d orbitals, so it cannot be correct.
How do the rates of diffusion of Ar (molar mass = 40) and Br2 (molar mass = 160) compare assuming both gases are at the same temperature and pressure?
Use Graham’s law, the rate of diffusion of gases are inversely proportional to the square root of their molar masses: v1/v2 = sqrt(m2/m1) so: v1/v2 = sqrt(160/40): Ar will diffuse twice as fast as Bromine.
Water can be a Bronsted Lowry base because it can:
Accept a proton.
Zn + HCl → ZnCl2 + H2
Consider the above unbalanced reaction. How many mL of a 4 M solution of HCl would be required to produce 22.4 L of H2 gas at STP?
Since the reaction is unbalanced, we should balance it first, so we see
Zn + 2HCl → ZnCl2 + H2
which means that we need 2 moles of HCl for each mole of H2 we want to produce. 22.4 L of gas at STP is 1 mole, so we need 2 moles of HCl to react. In a 4 M solution, 2 moles would be found in 1/2 L or 500 mL since the solution has 4 moles per liter and therefore 2 moles per half-liter.
How many moles of Na+ ions were are there in the initial Na2SO4 solution used in this reaction:
Initially, 15.0 mL of 0.300 M Pb(NO3)2 was mixed with 15.0 mL of 0.300 M Na2SO4. All the Pb(NO3)a reacted to form Compound A, a white precipitate. Compound A was removed by filtration.
- 009 moles. The initial solution in this reaction is 15 mL of 0.300 M Na2SO4:
(15. 0 mL)(1 L)(0.300 mol Na2SO4)(2 mol Na2+‑) / (1000 mL) (1 L Na2SO4)(1 mol Na2SO4) = 0.009 moles.
Pb(OH)2(s) is slightly soluble in water. How would the amount of Pb(OH)2(s) that normally dissolves in 1 L of water be affected if the pH were 9.0?
A) Less would dissolve
B) The same amount would dissolve
C) More would dissolve
D) There is no way to predict the effect of the change in pH of the water
(A). Less would dissolve. At pH 9, the concentration of OH- is greater than the concentration of OH- at pH 7.Pb(OH)s à Pb2+ + 2 OH- and so according to Le Chatelier’s Principle, with more products available, the reaction would shift toward the reactants