Chemistry Assignment 5
If you had an aqueous mixture that contained Ag+, K+, and Pb2+ cations, how many different solids could precipitate if a chloride solution was added?
2
What are the coefficients for the following reaction when it is properly balanced?
2,2,1,2
When the equation, ___N2 + ___H2 → ___NH3 is balanced, the coefficient of hydrogen is:
3 ___N2 + __3_H2 → __2_NH3
What are the coefficients for the following reaction when it is properly balanced?
A) 2, 1, 1, 1
Which is a spectator ion from the following complete ionic equation: H+(aq) + Br-(aq) + K+ (aq) + OH-(aq) → H2O(l) + K+(aq) + Br- (aq)
A) K+
Which of the following is NOT an acid?
A. HCLO4 B.HNO3 C.HC2H3O2 D. H2SO4 E. None of the above E
Considering the following precipitation reaction: Pb(NO3)2(aq) + 2KI(aq) → PbI2(s) + 2KNO3(aq) Which ion(s) would NOT be present in the net ionic equation
B) K+, NO3-
Evidence of a redox reaction is when one substance transfers protons to another substance.
False
The properties of a compound are an average of the properties of the individual elements they are composed of.
False
The following reaction is correct balanced equation: AgNO3 + 2NH4Cl → AgCl + (NH4)2NO3
False ; Not a balance equation, since the formula (NH4)2NO3 is wrong, it should be NH4NO3
Combustion (Burning) reaction of any hydrocarbon (eg CH4), will always produce smoke along with carbon dioxide and water.
False, Combustion of hydrocarbon if happens in enough oxygen, only products are carbon dioxide and water; when combustion happens with less oxygen/ air: some unburnt carbon remained and is visible in form of smoke
The following equation IS balanced: CH4 + 2O2 → CO2 + H2O
False, left side has 4H, and 4 O but right side have only 2H and 3O, so not balanced
The net ionic equation for the reaction of sodium hydroxide plus hydrochloric acid is NaOH (aq) + HCl (aq) → NaCl (aq) + H2O (l) .
False; Net equation will be H+ (aq) + Cl- → H2O (l), everything else will cancel out since they are spectator ions
Mixing two aqueous solutions will always result in formation of a precipitate.
False; it can form a precipitate but not always, its possible to form two compounds which are both aqueous and hence no reaction,
When Ca(HCO3)2 is heated, Ca(CO3)2 is produced along with carbon dioxide and water
False; it produces calcium carbonate but correct formula of calcium carbonate is CaCO3
The reaction of carbonate ion with magnesium ion to form solid magnesium carbonate is an example of an oxidation reduction reaction.
False; oxidation reduction reaction must include transfer of ions. So when Mg changed to Mg 2+ ion, it was redox reaction. But its stated here that this is directly the reaction of Magnesium and carbonate ions, so not a redox reaction
Which of the following compounds is INSOLUBLE?
Magnesium Phosphate
What type of a reaction occurs when a potassium nitrate solution is mixed with a barium acetate solution?
No reaction
Which of the following everyday substances does NOT typically contain an acid?
Soaps
A precipitate will form when you mix solutions of potassium chloride and lead nitrate.
True
Decomposition reactions usually require energy to initiate the reaction.
True
In physical changes, the atoms or molecules that compose the matter do not change their identity, even though the matter may change its appearance.
True
Mixing HNO3 (aq) and NaHCO3 (aq) will produce carbon dioxide gas as a product.
True
We remove the spectator ions from the complete ionic equation to form the net ionic equation.
True
The reaction 2 KClO3 → 2 KCl + 3 O2 would be correctly classified as a decomposition reaction.
True, Reactants are complex products and products are simplified so it's a decomposition reaction
Li+, Na+, K+ and NH4+ compounds are soluble.
True, all compounds containing Li+, Na+, K+ and NH4+ ions are soluble: solubility chart : rule 1.
A strong electrolyte solution contains ionic compounds that completely dissociate in water.
True, ionic compound: soluble in water must be strong electrolyte Insoluble ionic compound: non electrolyte Sparingly (partially soluble) ionic compounds: weak electrolyte
A spectator ion is one that does not actively participate in a chemical reaction.
True, spectator ions remains same before and after the reaction, and cancels out, so it doesn't actively participate in the reaction
When balancing a chemical equation you may alter the coefficients but not the subscripts in the equation.
True, subscripts are fixed for a chemical compound, you cannot change them for balancing. But coefficient can be altered to balance a equation.
When compounds containing polyatomic ions dissolve, the polyatomic ions usually dissolve as intact units.
True, that's why they are called polyatomic ions, eg when sodium nitrate NaNO3 dissolves in water, it will give Na+ ion and nitrate ion (NO3-), since nitrate is a polyatomic ion
The formation of a new solid or gas is evidence of a chemical reaction.
True; both formation of solid, or evolution of gas are signs of chemical reaction
