In an endothermic reaction what is true of the enthalpy

Air has a mass of 1.2g and a volume of 4,555ml. What is the density

coldgirl [10]

Answer:

<h2>Density = 0.00026 g/mL</h2>

Explanation:

The density of a substance can be found by using the formula

<h3> $Density(\rho) = \frac{mass}{volume}$ </h3>

From the question

mass of air = 1.2 g

volume = 4,555 mL

Substitute the values into the above formula and solve for the density

That's

<h3> $Density = \frac{1.2}{4555}$ </h3>

= 0.0002634

We have the final answer as

<h3>Density = 0.00026 g/mL</h3>

Hope this helps you

3 0

3 years ago

1.42 mol sample of neon gas at a temperature of 13.0 °C is found to occupy a volume of 25.5 liters. The pressure of this gas sam

Dima020 [189]

Answer: 996 mmHg

Explanation:

According to avogadro's law, 1 mole of every substance occupies 22.4 L at NTP, weighs equal to the molecular mass and contains avogadro's number $6.023\times 10^{23}$ of particles.

According to the ideal gas equation:

$PV=nRT$

P = Pressure of the gas = ?

V= Volume of the gas = 25.5 L

T= Temperature of the gas = 13°C = (273+13) K = 286K

R= Gas constant = 0.0821 atmL/K mol

n= moles of gas= 1.42

$P=\frac{nRT}{V}=\frac{1.42\times 0.0821\times 286}{25.5}=1.31atm=996mmHg$ (760mmHg=1atm)

Thus pressure of this gas sample is 996 mm Hg.

3 0

3 years ago

A 33.0 mL sample of 1.15 M KBr and a 59.0 mL sample of 0.660 M KBr are mixed. The solution is then heated to evaporate water unt

Oksi-84 [34.3K]

Answer:

We need 13.06 grams of silver nitrate to precipitate out silver bromide in the final solution

Explanation:

<u>Step 1:</u> Data given

Sample 1: The 1.15 M sample has a volume of 33.O mL

Sample 2: The 0.660 M sample has a volume of 59.0 mL

Molar mass of KBr = 119 g/mol

Molar mass of AgNO3 = 169.87 g/mol

<u>Step 2:</u> Calculate number of moles for both samples

Number of moles = Molarity * Volume

Sample 1: 1.15 M * 33 *10^-3 L = 0.03795 moles

Sample 2: 0.660 M *59*10^-3 L = 0.03894 moles

Total mol KBr = 0.03795 + 0.03894 = 0.07689 moles

<u>Step 3:</u> Calculate total mass

mass = Number of moles * Molar mass

mass = 0.07689 moles * 119 g/moles = 9.15 grams ( in 55mL)

<u>Step 4</u>: Calculate moles of AgBr

AgNO3 reacts with KBr

KBr(aq) + AgNO3(aq) → AgBr(s) + KNO3(aq)

1 mole of KBr consumed, needs 1 mole of AgNO3 to produce 1 mole of AgBr and 1 mole of KNO3

So 0.07689 moles of KBr wll need 0.07689 moles of AgNO3

<u>Step 5:</u> Calculate mass of silver nitrate

mass of AgNO3 = Moles of AgNO3 * Molar mass of AgNO3

mass of AgNO3 = 0.07689 moles * 169.87 g/mol = 13.06 grams

We need 13.06 grams of silver nitrate to precipitate out silver bromide in the final solution

8 0

3 years ago

The equation X + Y yields

masha68 [24]

Most likely the equation yields a new compound XY. This is a synthesis reaction. <span>Synthesis reaction is a reaction where two or more substances combine to form a new compound. It is a reaction which releases energy in the form of heat and light. Therefore, it is an exothermic reaction.</span>

6 0

3 years ago

1. a.) Calculate the wavelength of light which has a frequency of 5.25 x 10 14 Hz.

Scilla [17]

<h3>Answer:</h3>

5.71 × 10² nm

<h3>Explanation:</h3>

The product of wavelength and frequency of a wave gives the speed of the wave.

Therefore;

Velocity of wave = Wavelength × Frequency

c = f ×λ

In our case;

Frequency = 5.25 × 10^14 Hz

Speed of light = 2.998 × 10^8m/s

But;

λ = c ÷ f

= 2.998 × 10^8m/s ÷ 5.25 × 10^14 Hz

= 5.71 × 10^-7 m

But; 1 M = 10^9 nm

Therefore;

wavelength = 5.71 × 10^-7 × 10^9

= 5.71 × 10² nm

The wavelength of light wave 5.71 × 10² nm

3 0

3 years ago