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3 years ago

What must happen for heat to be transferred by thermal conduction?

Chemistry

2 answers:

blsea [12.9K]3 years ago

8 0

Answer:

Two Molecules must collide with each other

Explanation:

zaharov [31]3 years ago

5 0

Answer:

yh what he said

Explanation:

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Question 10 of 25

Over [174]

Answer: 0

Explanation: A P E X

5 0

2 years ago

Read 2 more answers

An analytical chemist weighs out 0.055g of an unknown triprotic acid into a 250mL volumetric flask and dilutes to the mark with

Katarina [22]

Answer:

Mass of the unknown acid is 4.0g

Explanation:

The determine the molar mass of the unknown acid, the steps below can be followed

Firstly, determine the concentration of the acid, the formula below can be used;

ConcA × Va/ConcB × Vb = Na/Nb

Where ConcA is the concentration of the unknown acid

ConcB is the concentration of the NaOH base

Va is the volume of acid and Vb is the volume of base

Since, the titration was said to have reached an equivalent point, it means the number of moles of the acid (Na) was equal to the number of moles of the base (Nb) and thus both will be assumed to be 1

Thus

ConcA × 250/0.13 × 6.6 = 1/1

ConcA = 0.13 × 6.6/250

ConcA = 0.003432M

Then, determine the actual number of moles (n) of the unknown acid used,

ConcA = no of moles of acid/volume of acid (in dm³ or L)

To convert mL to L, we divide by 1000

Hence, 250ml = 0.25L

0.003432 = n/0.25

n = 0.003432 × 0.25

n = 0.01373 moles

To determine the molar mass;

n = mass/molar mass

The mass was given in the question to be 0.055g

Thus

0.01373 = 0.055/molar mass

molar mass = 0.055/0.01373

molar mass = 4.0g

5 0

2 years ago

7. Ionic bonds are at one end of the bond spectrum. What kinds of bonds are at the other end?

blondinia [14]

Answer:

non-polar covalent bonds

this is when the electronegativity difference between the two non-metal atoms is very little to cause a partial charge (delta positive and delta negative; δ+ and δ-) on the atoms

4 0

2 years ago

At 63.5 C the vapor pressure of H2O is 175 torr and that of ethanol is 400 torr. A solution is made by adding equal masses of H2

xxTIMURxx [149]

Answer:

Moel fraction of ethanol in the solution = 0.28

Vapor pressure of the solution = 238 torr

Mole fraction of ethanol in the vapor = 0.47

Explanation:

Let's use 100 g of each substance as a calculus basis. Knowing that the molar mass of water is 18 g/mol and the molar mass of ethanol is 46 g/mol, the number of moles (n = mass/molar mass) of each one is:

nw = 100/18 = 5.56 mol

ne= 100/46 = 2.17 mol

The total number of moles is 7.73 mol, so the mole fraction of ethanol is

2.17/7.73 = 0.28

The mole fraction of water must be 0.72, so if we assume that the solution is ideal, by the Raoult's law, the solution vapor pressure is the sum of the multiplication of the mole fraction by the vapor pressure of each substance, thus:

P = 0.28*400 + 0.72*175

P = 238 torr

The partial pressure of each substance can be found by the multiplication of the molar fraction by the vapor pressure, thus:

Pw = 0.72*175 = 126 torr

Pe = 0.28*400 = 112 torr

To know the number of moles that is vaporized above the solution, we may use the ideal gas law:

PV = nRT

P/n = RT/V

R is the gas constant, T is the temperature and V is the volume, so they are the same for both water and ethanol, thus

Pw/nw = Pe/ne

126/nw = 112/ne

ne = (112/126)*nw

ne = 0.89nw

So, the mole fraction of ethanol is:

ne/(ne + nw) = 0.89nw/(0.89nw + nw) = 0.89/1.89 = 0.47

4 0

3 years ago

Chemical reactions are only able to occur in one direction. Chemical reactions are only able to occur in one direction. True Fal

blagie [28]

Answer:

False

Explanation:

While chemical reactions can proceed in the forward direction , they can in fact also proceed in the backward direction too. The direction they would proceed depends majorly on the state of chemical equilibrium at that particular time for that particular chemical reaction.

It should be known that when a chemical reaction proceeds in the forward way, more products are formed and the reactants are used up. If however, the chemical reaction proceed in the backward way, more reactants are formed and the products are used up.

A practical example is in the case of an exothermic reaction. This is one in which heat is released to the surroundings as a result of the reactants being at a higer energy level compared to the product. Now, depending on the prevailing equilibrium constraint, the reaction could proceed forward or backward.

If for example, the temperature is decreased, this is a constraint being applied to the equilibrium state. The chemical reaction would take a shift and will favor the forward reaction and more of the products will be formed. And also of the temperature is increased, it is the backward reaction that is favored

7 0

3 years ago