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3 years ago

Is dissolving salt a chemical change or physical change and why?

1 answer:

4 0

It's a physical change because the composition of the salt hasn't change. Only the change in substance/form has occured. To tell if something has undergone physical change is:

• Melting

• Boiling

• Freezing

• Condensing

• Breaking

• Bending

• Dissolving

• Molecules can change motion and proximity

To tell if something changed chemically:

• Molecules rearrange with other molecules to make new substance

• Can be production of flames

• Color change

• Bubbling/fizzing

• Temp. change

• change in composition

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Sulfur trioxide, so3, is made industrially in enormous quantities by combining oxygen and sulfur dioxide, so2. what amount (mole

DedPeter [7]

The answer is 37.5 moles

The explanation:

1- when we have the mass of SO3 in Kg so, first we have to convert it to grams:

mass = 3 * 1000 = 3000 g

2- we need to get the molar mass of SO3 :

molar mass of SO3 = 32 + (16*3)

= 80 g/mol

3- then we can use this formula to get number of moles:

moles = mass / molar mass

= 3000 g / 80 g/mol

= 37.5 moles

6 0

3 years ago

If the concentration of Mg2+ in the solution were 0.039 M, what minimum [OH−] triggers precipitation of the Mg2+ ion? (Ksp=2.06×

Elodia [21]

Answer:

2.30 × 10⁻⁶ M

Explanation:

Step 1: Given data

Concentration of Mg²⁺ ([Mg²⁺]): 0.039 M

Solubility product constant of Mg(OH)₂ (Ksp): 2.06 × 10⁻¹³

Step 2: Write the reaction for the solution of Mg(OH)₂

Mg(OH)₂(s) ⇄ Mg²⁺(aq) + 2 OH⁻(aq)

Step 3: Calculate the minimum [OH⁻] required to trigger the precipitation of Mg²⁺ as Mg(OH)₂

We will use the following expression.

Ksp = 2.06 × 10⁻¹³ = [Mg²⁺] × [OH⁻]²

[OH⁻] = 2.30 × 10⁻⁶ M

3 0

4 years ago

Pleasee help <br> will name brainliest

zmey [24]

Answer:

0.125. work- divide the volume value by 1000

873. work- multiply the length value by 100

98100. work- Conversion factor: 1 kg = 100000 cg

1) Centigram = Kilogram * 100000

2) Centigram = 0.981 * 100000

3) Centigram = 98100

285.65. work- 12.5°C + 273.15 = 285.65K

446.85. work- 720K − 273.15 = 446.85°C

346.25. work- 73.1°C + 273.15 = 346.25K

Explanation:

i hope this helps:) brainliest plss??

8 0

3 years ago

YALL I NEED HELP ASAP

masya89 [10]

Answer:

Yes

Explanation:

6 0

3 years ago

For the following reaction, 6.94 grams of water are mixed with excess sulfur dioxide . Assume that the percent yield of sulfurou

Alexxx [7]

<h3>Answer:</h3>

#a. Theoretical yield = 31.6 g

#b. Actual yield = 25.72 g

<h3>Explanation:</h3>

The equation for the reaction between sulfur dioxide and water to form sulfurous acid is given by the equation;

SO₂(g) + H₂O(l) → H₂SO₃(aq)

The percent yield of H₂SO₃ is 81.4%

Mass of water that reacted is 6.94 g

#a. To get the theoretical yield of H₂SO₃ we need to follow the following steps

Step 1: Calculate the moles of water

Molar mass of water = 18.02 g/mol

Mass of water = 6.94 g

But, moles = Mass/molar mass

Moles of water = 6.94 g ÷ 18.02 g/mol

= 0.385 mol

Step 2: Calculate moles of H₂SO₃

From the equation, the mole ratio of water to H₂SO₃ is 1 : 1

Therefore, moles of water = moles of H₂SO₃

Hence, moles of H₂SO₃ = 0.385 mol

Step 3: Theoretical mass of H₂SO₃

Mass = moles × Molar mass

Molar mass of H₂SO₃ = 82.08 g/mol

Number of moles of H₂SO₃ = 0.385 mol

Therefore;

Theoretical mass of H₂SO₃ = 0.385 mol × 82.08 g/mol

= 31.60 g

Thus, the theoretical yield of H₂SO₃ is 31.6 g

<h3>#b. Calculating the actual yield</h3>

We need to calculate the actual yield

Percent yield of H₂SO₃ is 81.4%

Theoretical yield is 31.60 g

But; Percent yield = (Actual yield/theoretical yield)×100

Therefore;

Actual yield = Percent yield × theoretical yield)÷ 100

= (81.4 % × 31.6) ÷ 100

= 25.72 g

The percent yield of H₂SO₃ is 25.72 g

6 0

3 years ago