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3 years ago

PLEASE CHECK MY ANSWERS I REALLY NEED HELP!!!!!

Chemistry

2 answers:

Vlad1618 [11]3 years ago

8 0

Answer:

Explanation:

Heat and temperature are not the same thing. They possess different unit. So statement is false.

Molecular motion depends upon temperature . It increases with temperature. So statement is false.

Radiation excites the motion of water molecules in the food raising their kinetic energy . Water molecules being polar in nature vibrates strongly under the influence of changing electric field of em waves..

When Δ H is negative , heat is evolved so statement is false.

Due to exothermic process , heat is evolved . So statement is true.

Endothermic process indicates that thermal energy is absorbed by the system.

The unit of specific heat is J/mol.C. So statement is false.

change in temperature = heat/(mass.specific heat) = 368/2.23 x 11.2 =14.73 degree C.

From the formula above , heat absorbed = 2.91 x 10.4 x 26 = 786.86 J or 790 J

Calorimeter operates on the principle of heat absorbed is equal to heat released

yan [13]3 years ago

3 0

Q9 7.9 x 10−1 kJ

Q10 The amount of heat transferred is independent of the mass of the sample being studied.

just took the test

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At a temperature of 274k, the gas in a cylinder has a volume of 4.0 liters. If the volume of the gas decrease to 2.0 liters, wha

irga5000 [103]

Answer:

The temperature will be 137 K for the gas pressure to remain constant

Explanation:

If the gas pressure keeps on constant, volume of the gas will be modified according to temperature.

V1 / T1 = V2 / T2

4L / 274K = 2L / T2

(4L / 274K) . T2 = 2L

T2 = 2L . (274K / 4L)

T2 = 137K

3 0

4 years ago

A gas occupies a volume of 410 mL at 27°C and 740 mm Hg pressure. Calculate the volume the gas

murzikaleks [220]

Answer:

The volume of gas is 58.22 L which will occupy at 250.°C and 680 mm Hg pressure.

Explanation:

Given:

Temperature = 27°C

To make it into kelvin = 27+273

= 300K

Pressure =740mm Hg

to make it in atm. = $\frac{740}{760}$

= 0.973atm

n = 2.3 moles

Volume of gas =?

As we know according to the formula

PV = nRT

$V= \frac{nRT}{P}$

On substituting the values

= $\frac{2.3\times0.0827\times300}{0.973}$

= 58.22 L

Therefore, 58.22L volume of gas will occupy at 250.°C and 680 mm Hg pressure.

8 0

3 years ago

fish give off the compound ammonia which has a pH above 7 to which class of compounds does ammonia belong

jasenka [17]

Answer:
The compound ammonia given by fish is alkaline

Explanation:
We can classify elements/compounds based on their pH values into three types:
acids: these are compounds having pH value lower than 7
neutral: these are compounds having pH value equal to 7
alkalies: these are compounds having pH values higher than 7

This is shown in the attached image

We are given that the pH of the compound ammonia generated by the fish is above 7.
According to the above explanation, compound ammonia would be an alkaline compound.

Hope this helps :)

5 0

3 years ago

You have been given a sample of an unknown

anastassius [24]

Answer:. an ionic compound

Explanation:

If it conducts electricity when molten, then it is an ionic compound. No covalent compound conducts electricity in molten state because their crystal lattice is not composed of ions. There are ionic solids which conduct electricity when molten but are insoluble in water such as alumina Al2O3. The solid is soluble in strong acid solutions.

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4 years ago

* Why does the mass of a substance remain the same after a chemical reaction?

Ierofanga [76]

ANSWER: because they are not created or destroyed they are just rearranged to form the products

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3 years ago