ANACHEM - MIDTERM Flashcards
Which of the following is the confirmatory
test for the presence copper ions?
Which of the following is the confirmatory
test for the presence copper ions?
In titration, the solution of known
concentration is the
-standard solution or
-titrant
The phosphorus in a sample of phosphorus
rock weighing 0.5428g is precipitated as
MgNH4PO4.6H2O and ignited to Mg2P2O7
If the ignited precipitate weighs 0.2234g.
Calculate the % of P2O5 in the sample
-26.25
The weight of MgNH4PO4.6H2O
-0.4927
A substance that dissolves in water and
conducts electricity when present in an
aqueous solution is
Ionic
Process that allows coagulated particles to
revert to disperse state is known as
Peptization
Which of the following cations is considered
most toxic heavy metal that could affect the
nervous system?
Mercury ion
A weak acid, HF, is in solution with
dissolved sodium fluoride, NaF to make
buffer solution. If HCl is added, which ion
will react with the extra hydrogen ions from
the HCl to keep the pH from changing?
OH-
A solution was known to contain both Ag+
ions and Bi3+ ions. Which of the following
could be added to separate them in such a
way that one ion would end up in a
precipitate, while the other remained in
solution?
HNO3
If 8.19g KIO3 is dissolved in enough water
to make 500.0mL of solution, what is the
molarity of the potassium iodate solution?
The molar mass of KIO3 is 214g/mol.
7.65 x 10^-2 M
A process in which equations are arranged
so that unwanted units cancel and only the
desired units will remain.
Dimensional analysis
The equation below shows the
decomposition of lead nitrate. How many
grams of oxygen gas are produced when
11.5 g NO is formed? (N -14 g/mol; O-16
g/mol)
2Pb(NO3)2(s) –> 2PbO(s) + 4NO2(g)+
O2(g
1.00g
Dispersed particles in liquid phase, that settles spontaneously.
Colloidal suspension
The compound P4S3 is used in matches. It reacts with oxygen to produce P4O10 and SO2. The unbalanced chemical equation is shown below.
P4S3(s) + O2(g) → P4O10(s) + SO2(g)
What mass of SO2 is produced from the combustion of 0.331 g P4S3?
0.289 g
An electrolyte that partially dissociates in water
Weak Electrolyte
In titrimetric analyses, secondary standards are usually standardized against a primary standard.
False
All of the following are colligative properties EXCEPT
gas solubility as a function of partial pressure above a solution (Henry’s law).
Which of the following compounds is the deep blue color complex of copper ion?
Cu(NH3)(^2+)4
Le Châtelier’s Principle states that if a chemical system at equilibrium is stressed,
the system will adjust to reduce the stress.
Sodium Hydroxide a common titrant in titration of bases is also considered as a primary standard.
False
A solution is prepared by dissolving 4.40g of KSCN in enough water to make 340mL of solution. What is the concentration of the solution?
0.133 M
A Bronsted-Lowry base is defined as:
a proton acceptor
Which of these compounds is most likely to be covalent?
CS2
A 1.45 g sample of chromium contains () atoms.
1.68 x 10^22
If 16.4 g of oxygen gas react with excess hydrogen, what mass of water is produced? 2H2(g) + O2(g) →2H2O(g)
18.5 g
Which of these compounds is most likely to be ionic?
ICl
Which of the following is the correct Kb expression for HPO4(^2-) if added to water?
Kb = [H2PO4-][OH-]/[HPO4(^2-)]
What is the mass percent of each element in sulfuric acid, H2SO4?
2.055% H, 32.69% S, 65.25% O
Which of the following statements concerning osmosis is/are CORRECT?
-Osmosis involves the movement of a solvent through a semipermeable membrane. OR
-Osmotic pressure is a colligative property.
The molar mass of boron is 10.81 g/mole. What is the mass of a single boron atom?
6.510 x 10^24g
What concentration unit is necessary for the calculation of vapor pressure lowering?
mole fraction
Which of the following is the strongest acid?
Oxalic Acid Ka = 5.9 × 10^-2
If a solution is prepared by dissolving 7.7g of lithium iodide, LiI, in enough water to make 400mL of solution, what is the %(w/v) of LiI?
1.9%
What volume of 6.0M HNO3 is required to prepare 250mL of 0.40M HNO3?
17ml
A 0.6025g sample of a chloride salt was dissolved in H2O and the chloride precipitated by adding excess silver nitrate. The precipitate of silver chloride was filtered, washed, dried and found to weigh 0.7134g. Calculate the % Cl in the sample.
29.29%
How many liters of 0.2805 M C4H12O6(aq) contain 1.000g of C6H12O6 ?
0.01979 L