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3 years ago

study figure 10-3. how much nitrogen-14 will be produced from a 200-g sample of carbon 14 after 17,190 years

1 answer:

8 0

For this problem, we use the formula for radioactive decay which is expressed as follows:

An = Aoe^-kt

where An is the amount left after time t, Ao is the initial amount and k is a constant.

We calculate as follows:

An = Aoe^-kt
0.5 = e^-k(5730)
k = 1.21x10^-4

An = Aoe^-kt
An = 200e^-1.21x10^-4(17190)
An = 25

Therefore, about 175g is produced.

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What is the density of chlorine gas (MM = 71.0glmol) at 1.50 atm and 25.0C

IrinaVladis [17]

Answer: D=4.35g/L

Explanation:

The formula for density is $D=\frac{M}{V}$ . M is mass in grams and V is volume in liters.

Since we are give pressure and temperature, we can use the ideal gas law to find moles/volume. FInding moles/volume would give us the base for density. All we would have to do is convert moles to grams.

Ideal Gas Law: PV=nRT

$\frac{n}{V} =\frac{P}{RT}$

$\frac{n}{V}=\frac{1.50 atm}{(0.08206Latm/Kmol)(25+274.15K)}$

$\frac{n}{V} =\frac{0.061309mol}{L}$

Now that we have moles, we can use molar mass of chlorine gas to find grams.

$0.061309mol*\frac{71.0g}{mol} =4.3529g$

With our grams, we can find our density.

$D=\frac{4.3529g}{L}$

We need correct significant figures so our density is:

$D=\frac{4.35g}{L}$

5 0

3 years ago

Determine the molar mass of Ze(NO3)2. (Ze=55.85 N=14.01 O=16.00) * Help

Arturiano [62]

Answer:

179.87 g/mol

Explanation:

First you need to determine the number of each elements in the molecule. This information comes from the molecular formula.

Ze(NO3)2 tells us that there is 1 Ze atom and 2 NO3 anions per molecule. each NO3 anion will have 1 nitrogen and 3 oxygens. Due to that, one molecule of Ze(NO3)2 will have 1 atom of Ze, 2 atoms of nitrogen (N), and 6 atoms of oxygen (O).

Next you need to add all of the individual atom's molar masses to get the over all molar masses. The molar masses of each element is in the question but it can also be found on the periodic table.

molar mass of Ze(NO3)2 = 55.85g/mol + (14.01g/mol*2) + (16.00g/mol*6)

molar mass of Ze(NO3)2 = 179.87 g/mol

I hope this helps.

5 0

2 years ago

An aqueous solution of potassium sulfate (K2SO4) has a freezing point of -2.24

iragen [17]

An aqueous solution of potassium sulfate exhibits colligative properties. Colligative properties are properties that depends on the concentration of a substance in a solution. These properties are freezing point depression, vapor pressure lowering, osmotic pressure and boiling point elevation. For this problem we use the concept of freezing point depression since we are given the freezing point of the solution. Freezing point depression is as:

ΔT = -k(f) x m x i
-2.24 - 0 = -1.86 x m x 3
m = 0.4014

Thus, the molality of the solution is 0.4014.

7 0

3 years ago

How many kilometers are there in 4.5 x 10^3 meters ?

Len [333]

1 meter = .001 kilometers so 4.5 x 10^3 = 4500 so .001 x 4500 = 4.5 kilo

7 0

3 years ago

What is the density of an object if its mass is 10 g and a volume of 2 mL?

Lilit [14]

Hi there! Let's solve this problem shall we!

⠀Volume = 10g

Mass = 2 mL

In this specific problem, they are asking us to find the density of the object. So, using the information given to us (volume and mass), let's solve the problem!

Now, if you remember, D = M ÷ V

So, let's fill in the blanks!

D = Our unknown value

M = 2mL

V = 10g

Here is the filled out formula:

D = M ÷ V

D = 2mL ÷ 10g

D = 5 g/mL

*Make sure you put the units for your final solution!*

4 0

1 year ago