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2 years ago

Which sentences describe ponds and lakes?

Chemistry

1 answer:

DedPeter [7]2 years ago

8 0

Answer:

" However, their size can vary from a few square meters to thousands of square kilometers."

"They can be seasonal, existing for a few months, or exist for hundreds of years or more. "

Explanation:

the first sentence is incorrect, many places that don't even get snow or cold weather have ponds and lakes. You wont find sea urchins, octopuses or starfish in ponds and lakes. Many lakes are not connected to the ocean.

You might be interested in

An oxygen atom has a mass of and a glass of water has a mass of . Use this information to answer the question below. Be sure you

MariettaO [177]

Answer:

Number of moles of oxygen atoms having equal mass as glass of water = 3.12 moles

Note: The given question is missing some figures. Here is a complete similar question below.

An oxygen atom has a mass of 2.66*10^-23 g and a glass of water has a mass of 0.050 kg. What is the mass of 1 mole of oxygen atoms? Round your answer to 3 significant digits. How many moles of oxygen atoms have a mass equal to the mass of a glass of water? Round your answer to 2 significant digits.

Explanation:

A mole of a substance contains the Avogadro number of particles = 6.02 * 10²³

Therefore a mole of oxygen atoms contains 6.02*10²³ atoms.

mass of 1 atom of oxygen = 2.66*10⁻²³ g

Mass of 1 mole of oxygen atoms = mass of 1 atom * number of atoms in 1 mole

Mass of 1 mole of oxygen atoms = 2.66*10⁻²³ g * 6.02*10²³ = 16. 01 g

Mass of a glass of water = 0.050 Kg or 50 g

To determine the number of moles of oxygen atoms that have a mass equal to a glass of water i.e. 50 g, the formula below is used;

number of moles = mass/molar mass

mass of oxygen atoms= 50 g, molar mass or mass of one mole of oxygen atoms = 16.01 g

Therefore, number of moles of oxygen atoms = 50 g / 16.01 g = 3.12 moles

4 0

2 years ago

Sulfur and oxygen react to produce sulfur trioxide. In a particular experiment, 7.9 grams of SO3 are produced by the reaction of

shutvik [7]

Answer:

79%

Explanation:

1) Balanced chemical equation:

2S + 3O₂ → 2SO₃

2) Mole ratio:

2 mol S : 3 mol O₂ : 2 mol SO₃

3) Limiting reactant:

Number of moles of O₂

n = 6.0 g / 32.0 g/mol = 0.1875 mol O₂

Number of moles of S:

n = 7.0 g / 32.065 g/mol = 0.2183 mol S

Ratios:

Actual ratio: 0.1875 mol O₂ / 0.2183 mol S =0.859

Theoretical ratio: 3 mol O₂ / 2 mol S = 1.5

Since there is a smaller proportion of O₂ (0.859) than the theoretical ratio (1.5), O₂ will be used before all S be consumed, and O₂ is the limiting reactant.

4) Calcuate theoretical yield (using the limiting reactant):

0.1875 mol O₂ / x = 3 mol O₂ / 2 mol SO₃

x = 0.1875 × 2 / 3 mol SO₃ = 0.125 mol SO₃

5) Yield in grams:

mass = number of moles × molar mass = 0.125 mol × 80.06 g/mol = 10.0 g

6) Percent yield:

Percent yield, % = (actual yield / theoretical yield) × 100

% = (7.9 g / 10.0 g) × 100 = 79%

6 0

2 years ago

Calculate the mass in grams of each of the following amounts: 1.002 mol of chromium 4.08 x 10-8 mol of neon

Pepsi [2]

Answer:

$Mass_{chromium}=52.1\ g$

$Mass_{neon}=8.23\times 10^{-7}\ g$

Explanation:

Calculation of the mass of chromium as:-

Moles = 1.002 moles

Molar mass of chromium = 51.9961 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$1.002\ mol= \frac{Mass}{51.9961\ g/mol}$

$Mass_{chromium}=1.002\times 51.9961\ g = 52.1\ g$

Calculation of the mass of neon as:-

Moles = $4.08\times 10^{-8}$ moles

Molar mass of neon = 20.1797 g/mol

Thus,

$1.002\ mol= \frac{Mass}{20.1797\ g/mol}$

$Mass_{neon}=4.08\times 10^{-8}\times 20.1797\ g = 8.23\times 10^{-7}\ g$

6 0

2 years ago

Three solutions contain a certain acid. The first contains 10% acid, the second 30%, and the third 50%. A chemist wishes to use

Fittoniya [83]

Answer:

To prepare 50L of 32% solution you need: 11L of 30% solution, 22L of 50% solution and 17L of 10% solution.

Explanation:

A 32% solution of acid means 32L of acid per 100L of solution. As the chemist wants to make a solution using twice as much of the 50% solution as of the 30% solution it is possible to write:

2x*50% + x*30% + y*10% = 50L*32%

130x + 10y = 1600 (1)

-Where x are volume of 30% solution, 2x volume of 50% solution and y volume of 10% solution-

Also, it is possible to write a formula using the total volume (50L), thus:

2x + x +y = 50L

3x + y = 50L (2)

If you replace (2) in (1):

130x + 10(50-3x) = 1600

100x + 500 = 1600

100x = 1100

x = 11L -Volume of 30% solution-

2x = 22L -Volume of 50% solution-

50L - 22L - 11L = 17 L -Volume of 10% solution-

I hope it helps!

8 0

2 years ago

Which of the following statements will decrease the amount of work the system could perform? (a) Add to the solution (b) Add sol

Dmitry_Shevchenko [17]

Answer:

Increase the concentration of the solution

Explanation:

Increasing the solute would increase the concentration. Increasing the solvent would decrease the concentration. For instance, if your lemonade was too tart, you would add more water to decrease the concentration

8 0

2 years ago