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3 years ago

Chose all of the correct statements pure vs mixture

Chemistry

1 answer:

GarryVolchara [31]3 years ago

6 0

Answer:

I think that a pure substance is a form of matter that has a constant composition and properties that are constant throughout the sample. Mixtures are physical combinations of two or more elements and/or compounds.

Explanation:

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3. Methane (CH4) behaves as an ideal gas under standard temperature and pressure conditions. What volume is occupied by 1 kg of

AlekseyPX

Answer:

1711.11L

Explanation:

Given parameters:

Mass of methane = 1kg = 1000

Temperature of gas = 35°C

Pressure of the gas = 0.9atm

Converting to the temperature to kelvin, we have:

35+ 273 = 308k

Solution

From the given parameters, we can solve this problem using the ideal gas equation which is combination of the gas laws. It is expressed below:

PV = nRT .......................(i)

Where P is the pressure of the gas

V is the volume of the gas

n is the number of moles

R is the gas constant

T is the temperature

Now, from the above parameters, we have two unknowns which are n and V.

To find the number of moles n, we use the expression below:

number of moles = $\frac{mass}{molar mass}$

molar mass of methane = 12 + (4x1) = 16g/mol

Number of moels of methane = $\frac{1000}{16}$ = 62.5mole

Now that we know the number of moles, we can make the unknown Volume the subject of the formula:

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

V = $\frac{62.5 x 0.082 x 308}{0.9}$ = 1711.11L

7 0

3 years ago

Which of the following is not a characteristic of a metal?

jolli1 [7]

Answer:

B. Poor conductor.

Explanation:

It cannot be A, as only 1 metal is not solid at room temp.

It cannot be C, as most metals are ductile.

It cannot be D, as most metals are malleable.

This leaves B, which is not true about metals, as a lot are very good conductors.

3 0

2 years ago

Carbon disulfide burns in oxygen to yield carbon dioxide and sulfur dioxide according to the following chemical equation. CS2(l)

Semmy [17]

Answer:

a) the limiting reactant is 02

b) There will remain 0.667 moles of CS2

c) There will be formed 0.333 moles oof CO2 and 0.667 moles of SO2

Explanation:

Step 1: Data given

Number of moles of CS2 = 1.00 mol

Number of moles of O2 = 1.00 mol

Molar mass of O2 = 32 g/mol

Molar mass of CS2 = 76.14 g/mol

Step 2: The balanced equation

CS2(l) + 3O2(g) → CO2(g) + 2SO2(g)

Step 3: Calculate the limiting reactant

For 1 mole of CS2 we need 3 moles of O2 to produce 1 mol of CO2 and 2 moles of SO2

O2 is the limiting reactant. It will completely be consumed.(1.00 mol).

CS2 is in excess. There will react 1.00/ 3 = 0.333 moles

There will remain 1.00 - 0.333 = 0.667 moles of CS2

Step 4: Calculate moles of CO2 and SO2

For 1 mole of CS2 we need 3 moles of O2 to produce 1 mol of CO2 and 2 moles of SO2

For 1.00 mol of O2 we have 1.00/3 = 0.333 moles CO2

For 1.00 mol of O2 we have 1.00 /(3/2) = 0.667 moles of SO2

8 0

3 years ago

a bright violet line occurs at 435.8 nm in the emission spectrum of mercury vapor. What amount of energy, in joules, must be rel

Readme [11.4K]

<h3>Answer:</h3>

4.56 × 10^-19 Joules

<h3>Explanation:</h3>

We are given;

Wavelength of the wave as 435.8 nm

We are required to calculate the amount of energy released by an electron.

We know that the speed of the wave, c is 2.998 × 10^8 m/s
But, c = f × λ , where f is the frequency and λ is the wavelength
Energy of a wave is given by the formula;

E = hf , where h is the plank's constant, 6.626 × 10^-34 J-s

But, f = c/λ

Therefore;

f = (2.998 × 10^8 m/s) ÷ (4.358 × 10^-7 m)

= 6.879 × 10^14 Hz

Thus;

Energy = 6.626 × 10^-34 J-s ×6.879 × 10^14 Hz

= 4.558 × 10^-19 Joules

= 4.56 × 10^-19 Joules

Therefore, the energy that must be released by the electron is 4.56 × 10^-19 Joules

7 0

3 years ago

The diagram shows changes of state between solid, liquid, and gas. The atoms of a substance lose energy during a change of state

Morgarella [4.7K]

P - solid to liquid.

8 0

3 years ago

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