**Answer:**

Mass of H₂SO₄ = 35.31 g

**Explanation:**

**Given data:**

Volume of H₂SO₄ solution = 3.0 L

Molarity of solution = 0.12 M

Mass of H₂SO₄ = ?

**Solution:**

**Formula:**

Molarity = number of moles / volume of solution in L

Now we will put the values.

0.12 M = number of moles / 3.0 L

Number of moles = 0.12 M × 3.0 L

Number of moles = 0.36 mol ( M = mol/L)

**Mass of H₂SO₄:**

Mass of H₂SO₄ = number of moles × molar mass

Mass of H₂SO₄ = 0.36 mol × 98.079 g/mol

Mass of H₂SO₄ = 35.31 g

Energy were released from the walnut, **q = 1,673.6 J**

<h3>Equation :</h3>

To find the **energy **using formula,

**q = mcΔt**

where,

q is charge

m is mass

c is **specific heat **of water

Δt is change in **temperature **

So, given

t₁ = 50°C

t₂ = 60°C

m = 40g

c = 4.184 J/g

Now putting the values known,

We get,

**q = mc(t₂ - t₁)**

q = 40g x 4.184 J/g x (60 - 50)

q = 167.36 J x 10

**q = 1,673.6 J**

<h3>What is heat energy?</h3>

Heat is the** thermal energy** that is transferred when two systems with different surface **temperatures **come into contact. Heat is denoted by the letters q or Q and is measured in **Joules**.

To know more abou**t specific heat :**

**brainly.com/question/11297584**

**#SPJ9**

**Answer:**

P₂ = 0.99 atm

**Explanation:**

**Given data:**

Initial pressure = 1.02 atm

Initial temperature = 11.2°C

Final pressure = ?

Final temperature = 4.00°C

**Solution:**

Initial temperature = 11.2°C (11.2+273 = 284.2 K)

Final temperature = 4.00°C (4.00+273 = 277 K)

According to Gay-Lussac Law,

The pressure of given amount of a gas is directly proportional to its temperature at constant volume and number of moles.

Mathematical relationship:

P₁/T₁ = P₂/T₂

Now we will put the values in formula:

1.02 atm / 284.2 K = P₂/277 K

P₂ = 1.02 atm × 277 K / 284.2 K

P₂ = 282.54 atm. K /293 K

P₂ = 0.99 atm

A question that can be tested scientifically are questions that can be answered through observations or through a well designed experiment that can provide evidence.

**Answer:**

222.3 ml of a 0.130 M aqueous solution of chromium (II) nitrate must be taken to obtain 5.08 grams of the salt.

**Explanation:**

Being:

- Cr: 52 g/mole
- N: 14 g/mole
- O: 16 g/mole

the molar mass of chromium (II) nitrate, Cr(NO₃)₂ is:

Cr(NO₃)₂ = 52 g/mole + 2* (14 g/mole + 3* 16 g/mole)= 176 g/mole

So: if 176 grams are present in 1 mole of the compound, 5.08 grams in how many moles of the compound will be present?

amount of moles=0.0289 moles

Molarity (M) is the number of moles of solute that are dissolved in a given volume. It is then calculated by dividing the moles of the solute by the volume of the solution:

Molarity is expressed in

So in this case:

- molarity= 0.130 M
- number of moles of solute= 0.0289 moles
- volume= ?

Replacing:

Solving:

volume=0.2223 liters

Being 1 L= 1,000 mL:

volume=0.222 liters= 222.3 mL

<u><em>**
222.3 ml of a 0.130 M aqueous solution of chromium (II) nitrate must be taken to obtain 5.08 grams of the salt.**</em></u>