Which of these forces does not act over a distance?

What is the molar mass of an element?

Vesnalui [34]

The answer is: the mass of 6.02 x 1023 representative particles of the element.

The base SI unit for molar mass is kg/mol, but chemist more use g/mol (gram per mole).

For example, molar mas of ammonia is 17.031 g/mol.

M(NH₃) = Ar(N) + 3 · Ar(H) · g/mol.

M(NH₃) = 14.007 + 3 · 1.008 · g/mol.

M(NH₃) = 17.031 g/mol.

The molar mass (M) is the mass of a given substance (in this example ammonia) divided by the amount of substance.

8 0

3 years ago

A sample of gas occupies a volume of 61.5 mL . As it expands, it does 130.1 J of work on its surroundings at a constant pressure

Lesechka [4]

Answer:

the final volume of the gas is $V_2$ = 1311.5 mL

Explanation:

Given that:

a sample gas has an initial volume of 61.5 mL

The workdone = 130.1 J

Pressure = 783 torr

The objective is to determine the final volume of the gas.

Since the process does 130.1 J of work on its surroundings at a constant pressure of 783 Torr. Then, the pressure is external.

Converting the external pressure to atm ; we have

External Pressure $P_{ext}$ :

$P_{ext} = 783 \ torr \times \dfrac{1 \ atm}{760 \ torr}$

$P_{ext} = 1.03 \ atm$

The workdone W = $P_{ext}$ V

The change in volume ΔV= $\dfrac{W}{P_{ext}}$

ΔV = $\dfrac{130.1 \ J \times \dfrac{1 \ L \ atm}{ 101.325 \ J} }{1.03 \ atm }$

ΔV = $\dfrac{1.28398717 }{1.03 }$

ΔV = 1.25 L

ΔV = 1250 mL

Recall that the initial volume = 61.5 mL

The change in volume V is $\Delta V = V_2 -V_1$

$- V_2= - \Delta V -V_1$

multiply through by (-), we have:

$V_2= \Delta V+V_1$

$V_2$ = 1250 mL + 61.5 mL

$V_2$ = 1311.5 mL

∴ the final volume of the gas is $V_2$ = 1311.5 mL

5 0

2 years ago

In this experiment, we will be performing a titration with a buret. place the steps in order. 1. record the ph when 0.0 ml of na

77julia77 [94]

I am guessing that your solutions of HCl and of NaOH have approximately the same concentrations. Then the equivalence point will occur at pH 7 near 25 mL NaOH.

The steps are already in the correct order.

1. Record the pH when you have added 0 mL of NaOH to your beaker containing 25 mL of HCl and 25 mL of deionized water.

2. Record the pH of your partially neutralized HCl solution when you have added 5.00 mL of NaOH from the buret.

3. Record the pH of your partially neutralized HCl solution when you have added 10.00 mL, 15.00 mL and 20.00 mL of NaOH.

4. Record the NaOH of your partially neutralized HCl solution when you have added 21.00 mL, 22.00 mL, 23.00 mL and 24.00 mL of NaOH.

5. Add NaOH one drop at a time until you reach a pH of 7.00, then record the volume of NaOH added from the buret ( at about 25 mL).

6. Record the pH of your basic HCl-NaOH solution when you have added 26.00 mL, 27.00 mL, 28.00 mL, 29.00 mL and 30.00 mL of NaOH.

7. Record the pH of your basic HCl-NaOH solution when you have added 35.00 mL, 40.00 mL, 45.00 mL and 50.00 mL of NaOH from your 50mL buret.

4 0

3 years ago

The difference between a solution and a mechanical mixture.

alina1380 [7]

Answer:

A mixture has more than one things that are not fused chemically

Explanation:

Mixture comprises two or three compounds that aren't fused chemically. They have no physical interactions. A solution contains two substances that are chemically mixed to form a new compound. The chemical properties of each substances are retained without change.

7 0

2 years ago

what is the molecular formula of a compound that contains 38% c, 45% n and 16% h if 0.157 g of the compound occupies 125 ml with

EastWind [94]

The molecular formula of the given compound is CH₅N.

<h3>What is the ideal gas equation?</h3>

The ideal gas law has defined the product of the volume and pressure as equal to the product of the gas constant (R) and absolute temperature of the gas.

The mathematical equation of the ideal gas law is as follows:

PV = nRT

The temperature of the compound, T = 22° C = 295 K

The pressure of the compound, P = 99.5 KPa = 0.982 atm

The volume of the compound, V = 125 ml = 0.125 L

0.125 × 0.982 = (0.157 g/M) × 0.082 ×295

M = 31 g/mol

A number of moles of C = 0.157 ×0.37/12 = 0.00484

A number of moles of N = 0.157 ×0.45/14 = 0.00504

A number of moles of H = 0.157 ×0.16/1 = 0.0251

The simplest ratio of C: N: H is 1 : 1 : 5

The empirical formula of the given compound is CH₅N.

The molecular formula of the compound is CH₅N as the molecular mass is equal to 31 g/mol.

Learn more about ideal gas equation, here:

brainly.com/question/3637553

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4 0

8 months ago