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4 years ago

What environmental effect has cotton harvesting had in asia

1 answer:

7 0

It has used a lot of water to produce the cotton. The cotton also has hurt the environment because of all the chemicals that are applied. If the polluted water gets into the rivers or water ways, you now have a polluted body of water making it not safe.

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Is layers of sediment forming at the bottom of the ocean erosion?

kiruha [24]

Yes layers of sediment form at the bottom of the ocean.

5 0

3 years ago

Identify fossil types match each each type of fossil to its description

dem82 [27]

Well we need to see the fossil

4 0

3 years ago

Read 2 more answers

A sample of gold (Au) has a mass of 45.39 g.

professor190 [17]

1. What is the molar mass of gold?
Molar mass is a unit that expresses the mass of a molecule per one mol. The molar mass can be obtained by adding the neutron with the proton of the atoms. Gold has atomic number 79 so the proton is 79. The number of the neutron is 118. Then the molar mass would be: 79 + 118 = 197 g/mol

2. Calculate the number of moles of gold (Au) in the sample. Show your work.
In this question, you are given the mass of the gold and asked for how many moles the sample has. To find the number of moles you just need to divide the weight by the molar mass.
For 45.39 grams of gold, the number of moles would be:
45.39 / (197g/mol)= 0.23 moles

3. Calculate the number of atoms of gold (Au) in the sample. Show your work.Moles is unit of a number of molecules but 1 mol doesn't represent 1 molecule. The number of atoms can be obtained by multiplying the number of moles with Avogadro number. The calculation would be:
0.23 moles * (6.023 * 10^23 molecules/mol)= 1.387 * 10^23 molecules

8 0

3 years ago

Which postulate of Dalton's atomic theory was later proven wrong?

ruslelena [56]

Answer:

Option c and d

Explanation:

John Dalton. In 1808, John Dalton proposed a theory known as Dalton’s Atomic Theory. The theory was published in a paper titled “A New Chemical Philosophy”. This theory was new to that era

The 5 postulates of Daltons' atomic theory are:

1. All the matters are made of atoms.

2. Atoms of different elements combine to form compounds

3. Compounds contain atoms in small whole-number ratios

4. Atoms can neither be created nor destroyed . (This was later proven wrong )

5. All atoms of an element are identical and have the same properties (This was later proven wrong as atoms of same element may be different in case of elements having isotopes )

Therefore, options c and d are the answer.

6 0

3 years ago

A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium.

Aleks [24]

PRACTICE MULTIPLE CHOICE QUESTIONS FROM UNIT 10

1.) A cylinder is filled with 2.00 moles of nitrogen, 3.00 moles of argon, and 5.00 moles of helium. If

the gas mixture is at STP, what is the partial pressure of the argon?

(A) 152 torr (B) 228 torr (C) 380. torr (D) 760. torr

2.) Compared to the average kinetic energy of 1 mole of water at 0 oC, the average kinetic energy

of 1 mole of water at 298 K is

(A) the same, and the number of molecules is the same

(B) the same, but the number of molecules is greater

(D) greater, but the number of molecules is the same

3.) If the pressure on a given mass of gas in a closed system is increased and the temperature

remains constant, the volume of the gas will

(A) decrease (B) increase (C) remain the same

4.) Which gas has approximately the same density as C2H6 at STP?

(A) NO (B) NH3 (C) H2S (D) SO2

5.) At a temperature of 273 K, a 400. milliliter gas sample has a pressure of 760. millimeters of

mercury. If the pressure is changed to 380. millimeters of mercury, at which temperature will

this gas sample have a volume of 551 milliliters?

(A) 100 K (B) 188 K (C) 273 K (D) 546 K

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5 0

3 years ago

Read 2 more answers