How many traditional areas of study can chemistry be divided into

describe in general terms an experiment to determine the molal freezing point depression constant kf of water. Assume the availa

Dvinal [7]

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.

6 0

3 years ago

Fe(s) + O2 (g) → Fe3+ O2− What most likely happens during this reaction?

Musya8 [376]

Answer : The most likely happens during this reaction is, Oxidation-reduction

Explanation :

The balanced reaction will be,

$4Fe(s)+3O_2(g)\rightarrow 2Fe_2O_3(s)$

In this reaction, neutral iron loses 3 electrons and oxidizes in (+3) state, $Fe^{3+}$ and neutral oxygen gains 2 electrons and reduces in (-2) state, $O^{2-}$

When iron react with oxygen gas to give iron oxide. This process is known as iron rusting. During the reaction, oxidation-reduction process occurs.

Oxidation : It is a type of chemical reaction in which a substance loses its electrons. Or we can say that in oxidation, the oxidation number increases.

Reduction : It is a type of chemical reaction in which a substance gains its electrons. Or we can say that in reduction, the oxidation number decreases.

5 0

3 years ago

Balance the following reaction. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the

Vera_Pavlovna [14]

2NH₂ + O₂ → N₂ + 2H₂O

<u>Explanation:</u>

Balancing the equation means, the number of atoms on both sides of the equation must be the same.

In the case of the given equation, we have to find out whether it is balanced or not.

2NH₂ + O₂ → N₂ + 2H₂O

Atoms Number of atoms before balancing after balancing

LHS RHS LHS RHS

N 1 2 2 2

H 2 2 4 4

O 2 1 2 2

To balance the N atoms, we have to put 2 in front of NH₂, and then to balance the H, O atoms, we have to put 2 in front of H₂O, so that each atom in left hand as well as right hand side of the equation was balanced.

8 0

4 years ago

If two balls have the same volume, but ball A has twice as much mass as ball B, which one will have the greater density? ball A,

rewona [7]

Density (D) is defined as the amount or mass (m) of a substance present in a unit volume(V). It can be expressed mathematically as:

Density = Mass/Volume

i.e. D = m/V -------(1)

Units: g/cm3

a)

If m1, V1 and D1 = mass, volume and density respectively of ball A

m2, V2 and D2 = mass, volume and density respectively of ball B

It is given that: V1 = V2; but m1 = 2m2

Based on equation (1) we have:

D1/D2 = (m1/V1)* (V2/m2) = (2m2/V2)*(V2/m2) = 2

Thus, density of ball A is twice that of B.

Ans: Ball A will have a greater density than B

b)

If m1, V1 and D1 = mass, volume and density respectively of ball C

m2, V2 and D2 = mass, volume and density respectively of ball D

It is given that:

V1 = 3V2 and m2 = 1/3(m1) i.e m1 = 3m2

Therefore,

D1/D2 = (m1/V1)* (V2/m2) = (3m2/3V2)*(V2/m2) = 1

Thus, D1 = D2

Ans: Their densities are equal

c)

If m1, V1 and D1 = mass, volume and density respectively of ball P

m2, V2 and D2 = mass, volume and density respectively of ball Q

It is given that:

m1 = m2 but V1 = 2V2

Therefore,

D1/D2 = (m1/V1)* (V2/m2) = (m2/2V2)*(V2/m2) = 1/2

Thus, D1 = 1/2(D2)

Ans: Ball Q will have a greater density.

d)

If m1, V1 and D1 = mass, volume and density respectively of ball X

m2, V2 and D2 = mass, volume and density respectively of ball Y

It is given that:

V1 = 2V2 and m1 = 1/2(m2)

Therefore,

D1/D2 = (m1/V1)* (V2/m2) = ((1/2(m2)/2V2)*(V2/m2) = 1/4

Thus, D1 = 1/4(D2)

Ans: Ball Y will have a greater density.

5 0

3 years ago

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You are given three beakers of unknown liquids. One beaker contains pure water. One contains salt water. One contains sugar wate

sergeinik [125]

Trick question: you just stated everything in the beakers.

5 0

3 years ago

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