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3 years ago

5

which one of the following is an endothermic process?1.ice melting 2.water freezing 3.a boiling soup 4.the reaction of HCl and N

AOH,temperature increases

1 answer:

Llana [10]3 years ago

8 0

<span>From the above given choices :
melting is an endothermic process</span>

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Please fill out completely for my understanding. Thank-You!

Archy [21]

The atomic number,atomic mass,valence electrons and the formula for calculating the number of neutrons is also given.The following table has been completed below in the attachment.

Explanation:

Atomic Number:the number of protons /electrons present in the nucleus of an atom is called the atomic number.

Mass Number/Atomic Mass:the number of protons and neutrons present in a nucleus

<u>Example:</u> $C_{6} ^{12}$ ;here;6 implies the atomic number and 12 implies the mass number/atomic mass

<u><em>No.of neutrons=Mass number-Number of protons</em></u>

Valence electrons:the number of electrons present in the outer most shell of an atom are called valence electrons

<u>Example:</u>If we consider a carbon atom;as its <em>e</em><em>lectronic configuration is2,4 and</em> it belongs to 4th group.Therefore the number of valency electrons in carbon is <u>4.</u>

8 0

2 years ago

What is the partial pressure of 0.50 mol Ne gas combined with 1.20 mol Kr gas at a final pressure of 730 torr?

WARRIOR [948]

The partial pressure of 0.50 Ne gas is 214.71 torr

calculation

the partial pressure of Ne = moles of Ne/total moles x final pressure

find the total moles of the air mixture

that is moles of Ne + moles of K= 0.50 + 1.20 = 1.70 moles

The partial pressure is therefore = 0.50 /1.70 x 730 = 214.71 torr

8 0

3 years ago

Read 2 more answers

Equal moles of H2, N2, O2, and He are placed into separate containers at the same temperature. Assuming each gas behaves ideally

lbvjy [14]

Answer:

They would all exhibit the same pressure.

Explanation:

Since the same number of mole of each gas is placed in different containers, it means the gas will occupy the same volume.

Now, the gases were observed at the same temperature. This means they will all have the same pressure as their volume is the same.

Now we can further understand this by doing a simple calculation as follow:

Assumptions:

For H2:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, H2 has a pressure of 1 atm.

For N2:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, N2 has a pressure of 1 atm

For O2:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, O2 has a pressure of 1 atm

For He:

Number of mole (n) = 1 mole

Volume (V) = 22.4L

Temperature (T) = 298K

Gas constant (R) = 0.0821 atm.L/Kmol

Pressure =..?

PV = nRT

Divide both side V

P = nRT /V

P = 1 x 0.0821 x 298 / 22.4

P = 1 atm

Therefore, He has a pressure of 1 atm.

From the above illustrations we can see that the gases have the same pressure since they have the same number of mole, volume and were observed at the same temperature.

4 0

3 years ago

An unknown aqueous metal analysis yielded a detector response of 0.255. When 1.00 mL of a solution containing 100.0 ppm of the m

AVprozaik [17]

Answer:

1.022ppm is the unknown concentration of the metal

Explanation:

Based on Lambert-Beer law, the increasing in signal of a detector is directly proportional to its concentration.

The unknown concentration (X) produces a signal of 0.255

99mL * X + 1mL * 100ppm / 100mL produces a signal of 0.502

0.99X + 1ppm produce 0.502, thus, X is:

0.255 * (0.99X + 1 / 0.502) =

X = 0.503X + 0.508

0.497X = 0.508

X =

1.022ppm is the unknown concentration of the metal

3 0

2 years ago

What volume of 17.8 M stock sulfuric acid solution would be needed to make 2.0L of 0.200 M diluted sulfuric acid solution?

vodomira [7]

Answer:

Required Volume is 22.47ml

Explanation:

To make 2.0L of 0.2M sulfuric acid required moles = 0.2 x 2 = 0.4 moles

To get 0.4 from 17.8M required quantity = 1000/17.8 x 0.4 = 22.47ml

7 0

3 years ago