JLABS EXAM QUESTIONS WITH 100% VERIFIED ANSWERS
When 1 g of sodium chloride (NaCl) is placed in 100 g of water, a solution results.
Once the solution is prepared, water is now considered what part of the solution? -
ANSWER Solvent
How many electrons does the iron ion have when it forms the ionic compound
FeCl3? - ANSWER 23
What is the volume of the water in this graduated cylinder? - ANSWER 4.39 mL
The product in a balanced reaction is 4Al2O3. Which of the following shows the
number of aluminium and oxygen atoms in 4Al2O3? - ANSWER 8 atoms of
aluminum and 12 atoms of oxygen
For an equal mass of each substance, which one will require the least amount of
heat to raise its temperature from 20°C to 30°C? - ANSWER Glass
For an equal mass of each substance, which one will require the least amount of
heat to raise its temperature from 20°C to 30°C? - ANSWER 67.2 L
Which substance will release the greatest amount of heat when 1.00 mol is frozen?
- ANSWER Benzene
A student hypothesizes that bromine (Br) has different chemical properties from
krypton (Kr). The periodic table supports this hypothesis by indicating that - -
ANSWER bromine and krypton have different numbers of valence electrons
A mixture of gases with a pressure of 800 mmHg contains 10% oxygen and 90%
nitrogen by volume. What is the partial pressure of the oxygen gas in the mixture? -
ANSWER 80 mmHg
Zn(s) + 2HCl(aq) → ZnCl2 + H2(g)
What type of reaction is shown? - ANSWER Single Replacement
Hydrogen chloride is a covalent compound. Which is the correct Lewis dot
structure for HCl? - ANSWER ..
H:Cl:
, .. All dots surrounding Cl none around H
Which is the best use for a fume hood? - ANSWER Removing toxic vapors
Which of the following equations is balanced? - ANSWER 2Na + Cl2 → 2NaCl
The picture shows a small section of elements from the periodic table. Which
element has one more proton than element X? - ANSWER 4
An example of a chemical property is - ANSWER tendency to undergo oxidation
What is the name for the compound CaSO4? - ANSWER Calcium sulfate
Which of these best describes the basis on which new scientific ideas are accepted
or rejected? - ANSWER Compelling evidence
The number of molecules in 48.0 grams of oxygen gas (O2) is - ANSWER 9.03 ×
1023
Al(s) + 3AgNO3(aq) → Al(NO3)3(aq) + 3Ag(s)
This equation represents which type of chemical reaction? - ANSWER
Single-replacement
In the formula for barium chloride, (BaCl2), barium (Ba) is written first because it
is - ANSWER the positive ion
Which of these laboratory techniques is best to separate a solid from a liquid to
recover the liquid? - ANSWER Filtering
Which of these is NOT required to ensure that stock solutions are free of
contamination? - ANSWER Store all solutions in brown bottles
When 1 g of sodium chloride (NaCl) is placed in 100 g of water, a solution results.
Once the solution is prepared, water is now considered what part of the solution? -
ANSWER Solvent
How many electrons does the iron ion have when it forms the ionic compound
FeCl3? - ANSWER 23
What is the volume of the water in this graduated cylinder? - ANSWER 4.39 mL
The product in a balanced reaction is 4Al2O3. Which of the following shows the
number of aluminium and oxygen atoms in 4Al2O3? - ANSWER 8 atoms of
aluminum and 12 atoms of oxygen
For an equal mass of each substance, which one will require the least amount of
heat to raise its temperature from 20°C to 30°C? - ANSWER Glass
For an equal mass of each substance, which one will require the least amount of
heat to raise its temperature from 20°C to 30°C? - ANSWER 67.2 L
Which substance will release the greatest amount of heat when 1.00 mol is frozen?
- ANSWER Benzene
A student hypothesizes that bromine (Br) has different chemical properties from
krypton (Kr). The periodic table supports this hypothesis by indicating that - -
ANSWER bromine and krypton have different numbers of valence electrons
A mixture of gases with a pressure of 800 mmHg contains 10% oxygen and 90%
nitrogen by volume. What is the partial pressure of the oxygen gas in the mixture? -
ANSWER 80 mmHg
Zn(s) + 2HCl(aq) → ZnCl2 + H2(g)
What type of reaction is shown? - ANSWER Single Replacement
Hydrogen chloride is a covalent compound. Which is the correct Lewis dot
structure for HCl? - ANSWER ..
H:Cl:
, .. All dots surrounding Cl none around H
Which is the best use for a fume hood? - ANSWER Removing toxic vapors
Which of the following equations is balanced? - ANSWER 2Na + Cl2 → 2NaCl
The picture shows a small section of elements from the periodic table. Which
element has one more proton than element X? - ANSWER 4
An example of a chemical property is - ANSWER tendency to undergo oxidation
What is the name for the compound CaSO4? - ANSWER Calcium sulfate
Which of these best describes the basis on which new scientific ideas are accepted
or rejected? - ANSWER Compelling evidence
The number of molecules in 48.0 grams of oxygen gas (O2) is - ANSWER 9.03 ×
1023
Al(s) + 3AgNO3(aq) → Al(NO3)3(aq) + 3Ag(s)
This equation represents which type of chemical reaction? - ANSWER
Single-replacement
In the formula for barium chloride, (BaCl2), barium (Ba) is written first because it
is - ANSWER the positive ion
Which of these laboratory techniques is best to separate a solid from a liquid to
recover the liquid? - ANSWER Filtering
Which of these is NOT required to ensure that stock solutions are free of
contamination? - ANSWER Store all solutions in brown bottles
