All categories

3 years ago

Which change is exothermic

2 answers:

7 0

Fusion, vaporization, and sublimation are endothermic processes, whereas freezing, condensation, and deposition are exothermic processes. Changes of state are examples of phase changes, or phase transitions. All phase changes are accompanied by changes in the energy of a system.

Ivan3 years ago

7 0

To add to that: exothermic is release of heat, endothermic is the opposite.

You might be interested in

What is an emission spectra and how would you view one?

alexandr1967 [171]

Answer:

The emission spectrum is formed when the electrons of a particular atom absorb energy and are excited (in this case by heating), reaching higher energy levels.

You can see it for example with an experiment where we light alcohol mixed with banana chips (it has potassium). The burning alcohol emits heat that makes potassium atoms excite and these in turn emit something red, orange light. If we add for example boric acid you see a green light.

Explanation:

8 0

3 years ago

All atoms that react

gregori [183]

Need more to the question

5 0

4 years ago

Is mud a heterogeneous or homogeneous mixture?

Lemur [1.5K]

Answer:

Heterogenous

Explanation:

Mud is a mixture of water and soil

8 0

3 years ago

Read 2 more answers

Balance the following chemical equation

ratelena [41]

Answer:

Explanation:

4). Ca(NO₃)₂ + Na₂SO₄ → CaSO₄ + 2Na(NO₃)₂

This question is incorrect.

Since, the final product by reacting Na⁺⁺ and NO₃⁻⁻ is NaNO₃

Correct equation will be,

Ca(NO₃)₂ + Na₂SO₄ → CaSO₄ + 2NaNO₃

This equation is in the balanced form.

5). Ni(NO₃)₂ + KI → NiI + 2K(NO₃)₂

Correct equation will be,

Ni(NO₃)₂ + KI → NiI₂ + 2KNO₃

[Since final product by reacting Ni⁺⁺ and I⁻ is NiI₂]

Balanced form of this equation will be,

Ni(NO₃)₂ + 2KI → NiI₂ + 2KNO₃

6). Ni(NO₃)₂ + KOH → NiOH + K(NO₃)₂

Correct form of the equation will be

Ni(NO₃)₂ + KOH → Ni(OH)₂ + KNO₃

[Since reaction of Ni⁺⁺ and OH⁻ gives Ni(OH)₂ and the reaction of K⁺ and NO₃⁻ gives KNO₃]

Now balancing this equation,

Ni(NO₃)₂ + KOH → Ni(OH)₂ + 2KNO₃

↓

Ni(NO₃)₂ + 2KOH → Ni(OH)₂ + 2KNO₃

8 0

4 years ago

How many liters of hydrogen gas will be produced at STP from the reaction of 5.159 x 1021 atoms of magnesium with 55.23 g of pho

shtirl [24]

Answer:

0.190L of hydrogen may be produced by the reaction.

Explanation:

Our reaction is:

3Mg + 2H₃PO₄ → Mg₃(PO₄)₂ + 3H₂

We need to determine the limting reactant. Let's find out the moles of each:

5.159×10²¹ atoms . 1 mol / 6.02×10²³ atoms = 0.00857 moles of Mg

55.23 g . 1 mol / 97.97 g = 0.563 moles of acid

2 moles of acid react to 3 moles of Mg

0.563 moles of acid may react to: (0.563 . 3) /2 = 0.8445 moles of Mg

Definetely the limting reactant is Mg.

As ratio is 3:3, 3 moles of Mg can produce 3 moles of hydrogen

Then, 0.00857 moles of Mg must produce 0.00857 moles of H₂

At STP, 1 mol of any gas occupies 22.4L

0.00857 mol . 22.4L / 1mol = 0.190L

3 0

3 years ago