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3 years ago

If 81g of water is measured out, how many moles are in the sample? *

Chemistry

1 answer:

valkas [14]3 years ago

7 0

Answer:

Explanation:

because moles = mass /mr

so 81/18(mr of H2O=2+16)

moles =4.5

hope this helps:)

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According to the following reaction, how many grams of water are produced in the complete reaction of grams of sulfuric acid?

Natasha2012 [34]

This question requires the mass of sulfuric acid and a balance equation. The complete question is given below

Question:

According to the following reaction, how many grams of water are produced in the complete reaction of 24.1 grams of sulfuric acid?

H₂SO₄(aq) + Zn(OH)₂(s) ---------> ZnSO₄(aq) + 2H₂O(l)

Answer:

8.85 grams of water is obtained from 24.1 grams of sulfuric acid according to the given reaction

Explanation:

In this problem, the mass of water can be determined by using the balanced chemical equation.

Step 1: Write all data

Molar mass of water = 18 g

Molar mass of sulfuric acid = 98 g

Given mass of sulfuric acid = 24.1 g

Mass of water from reaction = ?

Step 2: Write statement for conversion

Given equation shows that

1 mole of H₂SO₄ gives 2 moles of water

Step 3: Convert moles into molar mass

Convert the moles into molar mass so, the statement becomes,

98 g of H₂SO₄ gives (2)(18) g of water

1 g of H₂SO₄ gives (2)(18)/98 g of water

Step 4: Use given data

24.1 g of H₂SO₄ gives (2)(18)(24.1)/98 g of water

amount of water = 8.85 g

5 0

3 years ago

A certain orbital of the hydrogen atom has n = 4 and l = 2 what are the possible values of ml for this orbital?

Nadya [2.5K]

The ml is also called as the magnetic quantum number. The value of ml can range from –l to +l including zero. Hence all of the possible values for ml given that l = 2 are:

3 0

3 years ago

Derivative for tan(x)

Maksim231197 [3]

Answer:

sec² (x)

Explanation:

Use the trigonometric ratio definition of the tangent function and the quotient rule.

tan(x) = sin(x) / cos(x)

Quotient rule: the derivative of a quotient is:

[the denominator × the derivative of the numerator less the numerator × the derivative of the denominator] / [denominator]²

(f/g)' = [ g×f' - f×g'] / g²

So,

tan(x)' = [ sin(x) / cos(x)]'

[ sin(x) / cos(x)]' = [ cos(x) sin(x)' - sin(x) cos(x)' ] / [cos(x)]²

= [ cos(x)cos(x) + sin(x) sin(x) ] / [ cos(x)]²

= [ cos²(x) + sin²(x) ] / cos²(x)

= 1 / cos² (x)

= sec² (x)

The result is that the derivative of tan(x) is sec² (x)

4 0

3 years ago

An ionic compound is formed when there is a reaction between the elements

hjlf

Answer:

An ionic compound is formed when there is a reaction between the elements whose ions are electrostatically attracted.

Explanation:

The ionic compounds form crystalline networks with ionic bonding. Electrostatic attraction is a very strong bond that is very difficult to break. The stability of the ionic compound depends on the lattice energy, the higher it is, the more stable the compound is and the lattice energy is that which is released in the formation. At room temperature they are always in a solid state, because the bonds are very close and as stated before, they are difficult to break (providing a lot of energy)

4 0

3 years ago

(6 points) Calculate the maximum number of moles and grams of H2S that can form when 158 g of aluminum sulfide reacts with 131 g

Schach [20]

Answer:107.1 g, 124.1 g

Explanation:

The equation of the reaction is;

Al2S3(s) + 6H20(l) ----> 2Al(OH)3(s) + 3H2S(g)

Hence;

For Al2S3

Number of moles= reacting mass/molar mass

Number of moles = 158g/150gmol-1 =1.05 moles

If 1 mole of Al2S3 yields 3 moles of H2S

1.05 moles of Al2S will yield

1.05 × 3/1 = 3.15 moles

Mass of H2S = 3.15moles × 34 gmol-1 = 107.1 g

For water

Number of moles of water = 131g/18gmol-1= 7.3 moles

6 moles of water yields 3 moles of H2S

7.3 moles of water will yield 7.3 × 3/6 = 3.65 moles of H2S

3.65 moles × 34 gmol-1 =124.1 g

5 0

3 years ago