The speed of a wave on a rope is 50cm/s an its wave length is 10cm. What is its frequency

Lithium has an atomic mass of 6.941 amu. Lithium has two common isotopes. The one isotope has a mass of 6.015 amu and a relative

koban [17]

Answer:

The atomic mass of second isotope is 7.016

Explanation:

Given data:

Average Atomic mass of lithium = 6.941 amu

Atomic mass of first isotope = 6.015 amu

Relative abundance of first isotope = 7.49%

Abundance of second isotope = ?

Atomic mass of other isotope = ?

Solution:

Total abundance = 100%

100 - 7.49 = 92.51%

percentage abundance of second isotope = 92.51%

Now we will calculate the mass if second isotope.

Average atomic mass of lithium = (abundance of 1st isotope × its atomic mass) +(abundance of 2nd isotope × its atomic mass) / 100

6.941 = (6.015×7.49)+(x×92.51) /100

6.941 = 45.05235 + (x92.51) / 100

6.941×100 = 45.05235 + (x92.51)

694.1 - 45.05235 = (x92.51)

649.04765 = x 92.51

x = 485.583 /92.51

x = 7.016

The atomic mass of second isotope is 7.016

3 0

2 years ago

PLEASE HELP!!! The image represents the reaction between a certain number of molecules of N2 and H2.

77julia77 [94]

Answer:

The leftover reactant is the nitrogen gas, N₂.

Explanation:

As per your description:

1. Square on the left: N₂(g)

3 units of two joint circles: this represents 3 molecules of nitrogen gas, N₂(g).

2. Square on the right: H₂(g)

3 units of two joint circles: this represents 3 molecules of hydrogen gas, H₂(g).

3. Reaction

If the maximum possible amount of NH₃ is formed during the reaction, you assume that the reaction goes to completion.

The chemical equation that represents the reaction is:

N₂(g) + H₂(g) → NH₃(g)

Which must be balanced:

N₂(g) + 3H₂(g) → 2NH₃(g)

That means that 1 molecule (or 1 mol) of N₂(g) reacts with 3 molecules (or 3 moles ) of H₂(g) to produce 2 molecules (or 2 moles) of NH₃(g).

Since, the squares show that there are 3 molecules of each reactant, the 3 molecules of hydrogen gas will be able to react with 1 molecule of nitrogen gas. When that happens, all the hydrogen gas is consumend and yet two molecules of nitrogen gas will remain unreacted. Hence, the nitrogen gas is the leftover reactant.

4 0

2 years ago

Read 2 more answers

the hydrogen gas generated when calcium metal reacts with water is collected over water at 20 degrees C. The volume of the gas i

Gala2k [10]

Answer:

There is 0.0677 grams of H2 gas obtained

Explanation:

Step 1: Data given

The total pressure (988 mmHg) is the sum of the pressure of the collected hydrogen + the vapor pressure of water (17.54 mmHg).

ptotal = p(H2)+ p(H2O)

p(H2) = ptotal - pH2O = 988 mmHg - 17.54 mmHg = 970.46 mmHg

Step 2: Calculate moles of H2 gas

Use the ideal gas law to calculate the moles of H2 gas

PV = nRT

n = PV / RT

⇒ with p = pressure of H2 in atm = 970.46 mmHg * (1 atm /760 mmHg) = 1.277 atm

⇒ V = volume of H2 in L = 641 mL x (1 L / 1000 mL) = 0.641 L

⇒ n = the number of moles of H2 = TO BE DETERMINED

⇒ R = the gas constant = 0.08206 L*atm/K*mol

⇒ T = the temperature = 20.0 °C = 293.15 Kelvin

n = (1.277)(0.641) / (0.08206)(298.15) = 0.0335 moles H2

Step 3: Calculate mass of H2

Mass of H2 = moles H2 ¨molar H2

0.0335 moles H2 * 2.02 g/mol H2 = 0.0677g H2

There is 0.0677 grams of H2 gas obtained

7 0

2 years ago

One of the most important chemical reactions is the Haber process, in which N2 and H2 are converted to ammonia which is used in

Lera25 [3.4K]

Answer:

c) 22

Explanation:

Let's consider the following balanced equation.

N₂(g) + 3 H₂(g) ----> 2 NH₃(l)

According to the balanced equation, 34.0 g of NH₃ are produced by 1 mol of N₂. For 170 g of NH₃:

$170gNH_{3}.\frac{1molN_{2}}{34.0gNH_{3}} =5.00molN_{2}$

According to the balanced equation, 34.0 g of NH₃ are produced by 3 moles of H₂. For 170 g of NH₃:

$170gNH_{3}.\frac{3molH_{2}}{34.0gNH_{3}} =15.0molH_{2}$

The total gaseous moles before the reaction were 5.00 mol + 15.0 mol = 20.0 mol.

We can calculate the pressure (P) using the ideal gas equation.

P.V = n.R.T

where

V is the volume (50.0 L)

n is the number of moles (20.0 mol)

R is the ideal gas constant (0.08206atm.L/mol.K)

T is the absolute temperature (400.0 + 273.15 = 673.2K)

$P=\frac{n.R.T}{V} =\frac{20.0mol\times (0.08206atm.L/mol.K)\times 673.2K ) }{50.0L} =22.0atm$

7 0

2 years ago

How many grams are in 2.5 pound sample

julsineya [31]

About 2,500 grams Ans balkfdoaks;

5 0

2 years ago