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3 years ago

Two atoms that have the same number of protons must be the same__________.

Chemistry

1 answer:

bonufazy [111]3 years ago

4 0

Answer:

Element

Explanation:

Two of the same element may have differing numbers of neutrons, however, when it comes to protons, two of the same element will always have the same number of protons. Two different elements may have the same neutrons, but never protons.

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For each of the following pairs of substances, determine which has the larger molar entropy at 298 K: (A) Br₂(l) or (B) Cl₂(g) (

irakobra [83]

Explanation:

Entropy is defined as the degree of randomness present in a substance. Therefore, more is the irregularity present in a compound more will be its molar entropy.

Hence, decreasing order to molar entropy in state of matter is as follows.

Gases > Liquids > Solids

In the first pair, we are given $Br_{2}(l)$ or $Cl_{2}(g)$ . Since, molar entropy of liquids is less than the molar entropy of gases.

Hence, $Cl_{2}(g)$ will have larger molar entropy as compared to $Br_{2}(l)$ .

In the second pair, we are given Fe(s) or Ni(s). More is the molar mass of a compound more will its molar entropy. Molar mass of Fe is 55.84 g/mol and molar mass of Ni is 58.69 g/mol.

Hence, molar entropy of Ni(s) is more than the molar entropy of Fe(s).

In the third pair, we are given $C_{2}H_{6}(g)$ or $C_{2}H_{4}(g)$ . As both the given species are gaseous in nature. So, more is the molar mass of specie more will be its molar entropy.

Molar mass of $C_{2}H_{6}(g)$ is 30.07 g/mol and molar mass of $C_{2}H_{4}(g)$ is 28.05 g/mol. Therefore, molar entropy of $C_{2}H_{6}(g)$ is more than the molar entropy of $C_{2}H_{4}(g)$ .

In the fourth pair, we are given $CCl_{4}(g)$ or $CH_{4}(g)$ . Molar mass of $CCl_{4}(g)$ is 153.82 g/mol and molar mass of $CH_{4}(g)$ is 16.04 g/mol.

Therefore, molar entropy of $CCl_{4}(g)$ is more than the molar entropy of $CH_{4}(g)$ .

In the fifth pair, we are given HgO(s) or MgO(s). Molar mass of HgO is 216.59 g/mol and molar mass of MgO is 40.30 g/mol.

Hence, molar entropy of HgO(s) is more than the molar entropy of MgO.

In the fifth pair, we are given NaCl(aq) or $MgCl_{2}(aq)$ . Molar mass of NaCl 58.44 g/mol and molar mass of $MgCl_{2}(aq)$ is 95.21 g/mol.

Hence, the molar entropy of $MgCl_{2}(aq)$ is more than the molar entropy of NaCl(aq).

5 0

3 years ago

At what celsius temperature does 0.750mol of an ideal gas occupy a volume of 35.9L at 114kPa

pashok25 [27]

Answer:

378.25°C

Explanation:

Given data:

Number of moles of gas = 0.750 mol

Volume of gas = 35.9 L

Pressure of gas = 114 KPa (114/101 = 1.125 atm)

Temperature of gas = ?

Solution:

The given problem will be solve by using general gas equation,

PV = nRT

P= Pressure

V = volume

n = number of moles

R = general gas constant = 0.0821 atm.L/ mol.K

T = temperature in kelvin

now we will put the values.

T = PV/nR

T = 1.125 atm × 35.9 L /0.750 mol × 0.0821 atm.L/ mol.K

T = 40.3875/0.062/K

T = 651.4 K

Kelvin to °C:

651.4 K - 273.15 = 378.25°C

8 0

4 years ago

Be sure to answer all parts. For the titration of 10.0 mL of 0.250 M acetic acid with 0.200 M sodium hydroxide, determine the pH

DaniilM [7]

Explanation:

$Molarity=\frac{moles}{Volume(L)}$

Molarity of the acetic acid = 0.250 M

Volume of the acetic acid solution = 10.0 mL = 0.010 L( 1 mL =0.001L)

Moles of acetic acid ;

$n=0.250 M\times 0.010 L=0.0025 mol$

Molarity of the NaOH = 0.200 M

a) Volume of the NaOH solution = 10.0 mL = 0.010 L( 1 mL =0.001L)

Moles of NaOH : $0.200M\times 0.010 L=0.002 mol$

$CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O$

1 mole NaOH neutralizes 1 mole of acetic acid , then 0.002 moles of NaOH will neutralize 0.002 mol of acetic acid.

Moles of acetic acid left un-neutralized = 0.0025 mol - 0.002 = 0.0005 mol

1 mole of acetic acid gives 1 mole of hydrogen ion, then 0.0005 mole of acetic acid will give 0.0005 mole of hydrogen ions.

Moles of hydrogen ion= 0.0005 mol

Volume of the solution = 0.010 L+ 0.010 L = 0.020 L

$[H^+]=\frac{0.0005 mol}{0.020 L}=0.025 M$

The pH of the 10.0 mL of base added to acetic acid solution :

$pH=-\log[H^+]=-\log[0.025 M]=1.60$

b) Volume of the NaOH solution = 12.0 mL = 0.012 L( 1 mL =0.001L)

Moles of NaOH : $0.200M\times 0.012 L=0.0024 mol$

$CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O$

1 mole NaOH neutralizes 1 mole of acetic acid , then 0.0024 moles of NaOH will neutralize 0.0024 mol of acetic acid.

Moles of acetic acid left un-neutralized = 0.0025 mol - 0.0024 = 0.0001 mol

1 mole of acetic acid gives 1 mole of hydrogen ion, then 0.0001 mole of acetic acid will give 0.0001 mole of hydrogen ions.

Moles of hydrogen ion= 0.0001 mol

Volume of the solution = 0.010 L+ 0.012 L = 0.022 L

$[H^+]=\frac{0.0001 mol}{0.022 L}=0.0045 M$

The pH of the 12.0 mL of base added to acetic acid solution :

$pH=-\log[H^+]=-\log[0.0045 M]=2.34$

c) Volume of the NaOH solution = 15.0 mL = 0.015 L( 1 mL =0.001L)

Moles of NaOH : $0.200M\times 0.015 L=0.003 mol$

$CH_3COOH+NaOH\rightarrow CH_3COONa+H_2O$

1 mole NaOH neutralizes 1 mole of acetic acid , then 0.003 moles of NaOH will neutralize 0.003 mol of acetic acid.

All the moles of acetic acid will get neutralized by NaOH and un-neutralized sodium hydroxide will left over.

Moles of NaOH left un-neutralized = 0.003 mol - 0.0025 = 0.0005 mol

1 mole of NaOH gives 1 mole of hydroxide ion, then 0.0005 mole of NaOH acid will give 0.0005 mole of hydroxide ions.

Moles of hydroxide ion= 0.0005 mol

Volume of the solution = 0.010 L+ 0.015 L = 0.025 L

$[OH^-]=\frac{0.0005 mol}{0.025 L}=0.02 M$

The pOH of the 15.0 mL of base added to acetic acid solution :

$pOH=-\log[OH^-]=-\log[0.02 M]=1.70$

The pH of the 15.0 mL of base added to acetic acid solution :

$pH=14-pOH=14-1.70=12.3$

7 0

3 years ago

What makes the Earth go around the Sun?

vladimir1956 [14]

Answer:

Just as the Moon orbits the Earth because of the pull of Earth's gravity, the Earth orbits the Sun because of the pull of the Sun's gravity. ... This happens because the Earth has a velocity in the direction perpendicular to the force of the Sun's pull.

Explanation:

3 0

3 years ago

Using the Lewis dot Symbol Illustrate how the atoms are bonded in each of the following ionic compounds; thanks

Gre4nikov [31]

I’m not really sure but i think it’s 2.

6 0

3 years ago