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1 year ago

Find the mass in grams of 1.40x10^23 molecules of n2

1 answer:

7 0

<span>Avogadro's number represents the number of units in one mole of any substance. This has the value of 6.022 x 10^23 units / mole. This number can be used to convert the number of atoms or molecules into number of moles. We calculate as follows:

</span>1.40x10^23 molecules of N2 ( 1 mol / 6.022 x 10^23 molecules ) ( 28.02 g / mol ) = 6.51 g N2

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A student determines measures the mass of one mole of carbon and finds it to be 12.22 grams. if the accepted value is 12.11 gram

Gre4nikov [31]

Answer:-

0.91% is the students % of error

Explanation: -

Accepted value= 12.11 grams

Measured value = 12.22 grams

Error = 12.22-12.11 = 0.11 grams

Percentage error = $\frac{0.11 grams}{12.11 grams}$ x100

= 0.91 %

Thus 0.91% is the students % of error

5 0

1 year ago

A 0.580 g sample of a compound containing only carbon and hydrogen contains 0.480 g of carbon and 0.100 g of hydrogen. At STP, 3

Sati [7]

Answer:

Molecular formula for the gas is: C₄H₁₀

Explanation:

Let's propose the Ideal Gases Law to determine the moles of gas, that contains 0.087 g

At STP → 1 atm and 273.15K

1 atm . 0.0336 L = n . 0.082 . 273.15 K

n = (1 atm . 0.0336 L) / (0.082 . 273.15 K)

n = 1.500 × 10⁻³ moles

Molar mass of gas = 0.087 g / 1.500 × 10⁻³ moles = 58 g/m

Now we propose rules of three:

If 0.580 g of gas has ____ 0.480 g of C _____ 0.100 g of C

58 g of gas (1mol) would have:

(58 g . 0.480) / 0.580 = 48 g of C

(58 g . 0.100) / 0.580 = 10 g of H

48 g of C / 12 g/mol = 4 mol

10 g of H / 1g/mol = 10 moles

7 0

2 years ago

6. The half life for uranium-235 is 7.0x108 years.

kaheart [24]

Answer:

$\large \boxed{4.0}$

Explanation:

$\text{No. of half-lives} = 2.8 \times 10^{9 } \text{ yr} \times \dfrac{\text{1 half-life}}{7.0 \times 10^{8} \text{ yr}} = \textbf{4.0 half-lives}\\\\\text{The sample went through $\large \boxed{\textbf{4.0 half-lives}}$}$

4 0

2 years ago

How many moles are in 8.30x10^23 molecules of H2o

LUCKY_DIMON [66]

You multiply avogadro's number to what you were given.
8.30x10^23 * 6. 0221409x10^23
=1.357*10^25

That should be the right answer but I'm not sure. It has been awhile since I have done this.

4 0

1 year ago

Read 2 more answers

A driver with a nearly empty fuel tank may say she is "running on fumes."

tensa zangetsu [6.8K]

Answer:

The farthest the vehicle could travel (if it gets 20.0 miles per gallon on liquid gasoline) is 1.62 miles.

Explanation:

The automobile gas tank has a volume capacity of 15 gallons which can be converted to liters: 15 × 3.7854 = 56.781 liters

We can find the moles of gasoline by using the ideal gas equation: PV = nRT.

Make n (number of moles) the subject of the formula: n = PV/RT, where:

P = 747 mmHg

V = 56.781 liters

R (universal gas constant) = 0.0821 liter·atm/mol·K

T = 25 ∘C = (273 + 25) K = 298 K

1 atm (in the unit of R) = 760 mmHg

Therefore n = 747 × 56.781/(0.0821 × 760 × 298) = 2.281 mol.

Given that the molar mass of the gasoline = 101 g/mol,

the mass of gasoline = n × molar mass of gasoline = 2.281 mol × 101 g/mol = 230.38 g

the density of the liquid gasoline = 0.75 g/mL

In order to calculate the distance the vehicle can travel, we have to calculate volume of gasoline available = mass of the liquid gasoline ÷ density of liquid gasoline

= 230.38 g ÷ 0.75 g/mL = 307.17 mL = 0.3071 liters = 0.3071 ÷ 3.7854 = 0.0811 gallons

since the vehicle gets 20.0 miles per gallon on liquid gasoline, the distance traveled by the car = gallons available × miles per gallon = 0.0811 × 20 = 1.62 miles.

6 0

2 years ago