Answer:
≈29.94 [°C].
Explanation:
all the details are in the attachment, the answer is underlined with orange colour.
Answer:
pH = 3.65
Explanation:
given data
pKa of HNO2 = 3.40
nitrous acid (HNO2) = 0.110 M
NaNO2 = 0.200 M
to find out
What is the pH
solution
we get here ph for acidic buffer that is express as
pH = pKa + log(salt÷acid) ........................1
put here value and we get
pH = 3.40 + log(0.200÷0.110)
pH = 3.65
Correct Question:
A spectator ion is (Select all that apply.)
- a piece of french fry contaminating the reaction mixture
- an ionic component of a reactant that is unchanged by the reaction
-in this experiment, nitrate ion
- your eye, carefully watching the progress of the reaction
Answer:
- an ionic component of a reactant that is unchanged by the reaction
Explanation:
A spectator ion is an ion that exists as a reactant and a product in a chemical equation. A spectator ion is one that exists in the same form on both the reactant and product sides of a chemical reaction.
Spectator ions are ions that are present in a solution but don't take part in the reaction. When reactants dissociate into ions, some of the ions may combine to form a new compound. The other ions don't take part in this chemical reaction and are therefore called spectator ions.
The correct option is therefore the option;
- an ionic component of a reactant that is unchanged by the reaction
Answer : The correct option is, (C) 2, 4 and 5.
Explanation :
Combustion reaction : It is a type of reaction in which a hydrocarbon react with an oxygen molecule to give carbon dioxide, water as a product.
For example : Methane react with oxygen to give carbon dioxide and water.
In the given list of chemical substances, 
are in oxide form. They can not be both reactant and product of a single combustion reaction.
In the given list, 
is the only hydrocarbon which shows a combustion reaction. That means react with 
to give 
and 
as a product.
The balanced combustion reaction of is,
Therefore, the correct answer is, (C) 2, 4, and 5.
A solution (in this experiment solution of NaNO₃) freezes at a lower temperature than does the pure solvent (deionized water). The higher the
solute concentration (sodium nitrate), freezing point depression of the solution will be greater.
Equation describing the change in freezing point:
ΔT = Kf · b · i.
ΔT - temperature change from pure solvent to solution.
Kf - the molal freezing point depression constant.
b - molality (moles of solute per kilogram of solvent).
i - Van’t Hoff Factor.
First measure freezing point of pure solvent (deionized water). Than make solutions of NaNO₃ with different molality and measure separately their freezing points. Use equation to calculate Kf.
