Answer:
Dissolving ice tea mix in water is a chemical change
Explanation:
It is a chemical change because you can not bring back the ice tea mix back if you mix it in water.
Hope it helps
The mass of sodium sulphate, Na₂SO₄, required to prepare the solution is 10.65 g
<h3>How to determine the mole of sodium sulphate Na₂SO₄</h3>
- Volume = 250 mL = 250 / 1000 = 0.25 L
- Molarity = 0.3 M
Mole = Molarity x Volume
Mole of Na₂SO₄ = 0.3 × 0.25
Mole of Na₂SO₄ = 0.075 mole
<h3>How to determine the mass of sodium sulphate Na₂SO₄</h3>
- Molar mass of Na₂SO₄ = 142.05 g/mol
- Mole of Na₂SO₄ = 0.075 mole
Mass = mole × molar mass
Mass of Na₂SO₄ = 0.075 × 142.05
Mass of Na₂SO₄ = 10.65 g
Thus, 10.65 g of Na₂SO₄ is needed to prepare the solution.
Learn more about molarity:
brainly.com/question/15370276
The answer is 67 108.0888km/s.
Answer: 90.04°C
Explanation: <u>Calorimeter</u> is a device measures the amount of heat of a chemical or physical process. An ideal calorimeter is one that is well-insulated, i.e., prevent the transfer of heat between the calorimeter and its surroundings. So, the net heat change inside the calorimeter is zero:
Rearraging, it can be written as
showing that the heat gained by Substance 1 is equal to the energy lost by Substance 2.
In our case, water is gaining heat, because its temperature has risen and so, brass is losing energy:
Calculating:
![m_{w}.c_{w}.\Delta T=-[m_{b}.c_{b}.\Delta T]](https://tex.z-dn.net/?f=m_%7Bw%7D.c_%7Bw%7D.%5CDelta%20T%3D-%5Bm_%7Bb%7D.c_%7Bb%7D.%5CDelta%20T%5D)
![100.4.18.(18.4-15)=-[52.9.0.375.(18.4-T)]](https://tex.z-dn.net/?f=100.4.18.%2818.4-15%29%3D-%5B52.9.0.375.%2818.4-T%29%5D)
Note: final temperature is the same as the substances are in thermal equilibrium.
Solving:
418(3.4)= - 365.01 + 19.8375T
19.8375T = 1786.21
T = 90.04
The initial temperature for the sample of brass was 90.04°.
The atomic number or proton number (symbol Z) of a chemical element is the number of protons found in the nucleus of every atom of that element.
