How many molecules are in 0.79 moles of NH4?

Chemistry help please! I just need to make sure the answers correct.... Thank you!

Veronika [31]

1. At constant tempaerature and pressure, 3 tablets produce 600cm^3 of gas
Thus calculating for 1 tablet that produces 600 / 3 = 200 cm^3
So now two tablets produce 200 x 2 = 400 cm^3
2. We have the equation PV = nRT, n being the number of moles
Pressure P = 1,000 kPa
Volume V = 3 L
R = 8.31 L kPa/mol-K
Temperature T = 298 K
n = PV / RT = (1000 x 3) / (8.31 x 298) = 3000 / 2476.38 = 1.21 moles
Number of moles = 1.21 moles.

8 0

3 years ago

The concentration of Rn−222 in the basement of a house is 1.45 × 10−6 mol/L. Assume the air remains static and calculate the con

bonufazy [111]

<u>Answer:</u> The concentration of radon after the given time is $3.83\times 10^{-30}mol/L$

<u>Explanation:</u>

All the radioactive reactions follows first order kinetics.

The equation used to calculate half life for first order kinetics:

$t_{1/2}=\frac{0.693}{k}$

We are given:

$t_{1/2}=3.82days$

Putting values in above equation, we get:

$k=\frac{0.693}{3.82}=0.181days^{-1}$

Rate law expression for first order kinetics is given by the equation:

$k=\frac{2.303}{t}\log\frac{[A_o]}{[A]}$

where,

k = rate constant = $0.181days^{-1}$

t = time taken for decay process = 3.00 days

$[A_o]$ = initial amount of the reactant = $1.45\times 10^{-6}mol/L$

[A] = amount left after decay process = ?

Putting values in above equation, we get:

$0.181days^{-1}=\frac{2.303}{3.00days}\log\frac{1.45\times 10^{-6}}{[A]}$

$[A]=3.83\times 10^{-30}mol/L$

Hence, the concentration of radon after the given time is $3.83\times 10^{-30}mol/L$

7 0

3 years ago

In which row has Aaron made an error in his chart?

hammer [34]

Answer:Row 2

Explanation:

7 0

3 years ago

I do not know the answer. Please help

BaLLatris [955]

I am sorry I don't know, points are points though

4 0

2 years ago

Vanessa made a list comparing the differences between the outer coverings in plants and animals, but she made a mistake. Read th

jekas [21]

The difference between the outer covering of plants and animals is that plant cell has cellulose cell wall while animal cell is surrounded by a cell membrane

A cell is the structural and functional unit of an organism which is capable of existing alone as it contains organelles that perform specific functions.

The plant cell is covered by a rigid cell wall which contains cellulose as its outer covering.

The animal cell contains not cellulose cell wall at its out covering but instead it is covered by a cell membrane.

Therefore, the difference between the outer covering of plants and animals is that plant cell has cellulose cell wall while animal cell is surrounded by a cell membrane.

Learn more about cell here:

brainly.com/question/18243320

#SPJ1

5 0

2 years ago