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3 years ago

Which of the following statements is true?

Chemistry

2 answers:

Gekata [30.6K]3 years ago

8 0

Answer:

respuesta número tres

dezoksy [38]3 years ago

4 0

Answer: Option D.

Mechanical and chemical digestion occur in the mouth but only chemical digestion occur in the stomach.

Explanation:

Digestion is the breakdown of larger food particles into smaller ones that can be absorb by the body and pass out the waste product or undigested food. There are two methods digestion occurs in the body and they are; mechanical and chemical digestion.

Mechanical digestion is the physical breakdown of food into smaller pieces. It begins in the mouth when food are chewed.

Chemical digestion involves the breakdown of food into nutrients. This begin in the mouth when food is mixed with saliva and it continue in the stomach where enzymes act on the food.

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What information does the first quantum number of an electron give?

bazaltina [42]

Answer:

Explanation:

the first quantum number of an electron gives the information about the energy level the electron is in

4 0

2 years ago

a 1.25g sample of ore containing iron pyrite (FeS2) was pulverized and ignited in air, converting the FeS2 to Fe2O3 and SO2(g).

svp [43]

Answer:

28.9%

Explanation:

Let's consider the following balanced equation.

2 FeS₂ + 11/2 O₂ ⇒ Fe₂O₃ + 4 SO₂

We can establish the following relations:

The molar mass of Fe₂O₃ is 159.6 g/mol
1 mole of Fe₂O₃ is produced per 2 moles of FeS₂
1 mole of Fe is in 1 mole of FeS₂
The molar mass of Fe is 55.84 g/mol

The amount of Fe in the sample that produced 0.516 g of Fe₂O₃ is:

$0.516gFe_{2}O_{3}.\frac{1molFe_{2}O_{3}}{159.6gFe_{2}O_{3}} .\frac{2molFeS_{2}}{1molFe_{2}O_{3}} .\frac{1molFe}{1molFeS_{2}} .\frac{55.84gFe}{1molFe} =0.361gFe$

The percent of Fe in 1.25 g of the ore is:

$\frac{0.361g}{1.25g} .100\%=28.9\%$

4 0

3 years ago

Given the reaction agi(s) ↔ ag+(aq) + i-(aq) solution equilibrium is reached in the system when

Julli [10]

Missing question:
1) the rate of dissolving reaches zero
2) the rate of crystallization reaches zero 
3) the rate of dissolving is zero and the rate of crystallization is greater than zero.
4) both the rate of dissolving and the rate of crystallization are equal and greater than zero.

Answer is: 4) both the rate of dissolving and the rate of crystallization are equal and greater than zero.
Silver chloride (AgCl) dissolves and form silver and chlorine ions, in the same time silver and chlorine ions crystallizate and form solid salt silver chloride.
In equilibrium rates of dissolvinf and crysallization and concentration of ions do not change.

7 0

2 years ago

What causes an ionic bond to form? Look at the picture above

Gennadij [26K]

Attraction between a cation in one element and an anion in the other element

7 0

3 years ago

Read 2 more answers

in a mixture of 1.90 mol of gas, 0.85 mol are nitrogen (n2) molecules. what is the mole fraction of n2 in this mixture?

Nostrana [21]

0.447 is the mole fraction of Nitrogen in this mixture.

mole fraction of nitrogen= moles of nitrogen/total moles

mole fraction of nitrogen=0.85/1.90

mole fraction of nitrogen=0.447

The product of the moles of a component and the total moles of the solution yields a mole fraction, which is a unit of concentration measurement. Because it is a ratio, mole fraction is a unitless statement. The sum of the components of the mole fraction of a solution is one. In a mixture of 1 mol benzene, 2 mol carbon tetrachloride, and 7 mol acetone, the mole fraction of the acetone is 0.7. This is computed by dividing the sum of the moles of acetone in the solution by the total number of moles of the solution's constituents:

To know more about mole fraction visit : brainly.com/question/8076655

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4 0

9 months ago