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3 years ago

I NEED HELP PLEASE WITH THESE QUESTIONS :

Chemistry

2 answers:

Vesna [10]3 years ago

8 0

Answer:

They are all thermal energy.

Explanation:

They all use heat.

Luda [366]3 years ago

7 0

Answer:

1. Lighting a match uses chemical energy.

2. The evaporation of water is created from thermal energy.

3. Cooking an egg uses thermal energy to cook.

2. The condensation of water from vapor in the air uses thermal energy.

Explanation:

1. Lighting a match uses chemical energy which is then converted into thermal energy.

2. Evaporating water can be cause by hot items like the Sun which plays the most important role in our water cycle by evaporating water.

3. Cooking an egg uses thermal energy because it take the heat away from the object used to cook with it.

4. The condensation of water from vapor in the air is from cool surfaces.

You might be interested in

What is the reducing agent in the reaction below?

trapecia [35]

Al is the reducing agent.That is answer B is the above answer
Al acts as a strong reducing agent. It reduces crO3 to form cr while Al is oxidized to Al2O3. Al is capable to reduce cr since Al is higher in reactivity series than cr.

8 0

3 years ago

What is the concentration of 10.00 mL of HBr if it takes 16.73 mL of a 0.253 M LiOH solution to neutralize it?

Leni [432]

First. let's write the reaction formula: HBr +LiOH ----> LiBr + H₂O

let's get the moles of LiOH first

moles= Molarity x Liters

moles= 0.253 M x 0.01673 Liter= 0.00423 moles LiOH

using the balanced equation, you can see that 1 mol LiOH is equal to 1 mol HBr. so:

0.00423 mol LiOH = 0.00423 mol HBr

now let's find the concentration

molarity= mol/ Liters

0.00423 mol/ 0.01000 Liters= 0.423 M

3 0

4 years ago

The question is in the picture below

Rus_ich [418]

Answer:

$\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3$

Explanation:

Hess's Law of Constant Heat Summation states that if a chemical equation can be written as the sum of several other chemical equations, the enthalpy change of the first chemical equation is equal to the sum of the enthalpy changes of the other chemical equations. Thus, the reaction that involves the conversion of reactant A to B, for example, has the same enthalpy change even if you convert A to C, before converting it to B. Regardless of how many steps it takes for the reactant to be converted to the product, the enthalpy change of the overall reaction is constant.

With Hess's Law in mind, let's see how A can be converted to 2C +E.

$\bf{\text{A} \rightarrow 2\text{B}}$ (Δ $\text{H}_1$ ) -----(1)

Since we have 2B, multiply the whole of II. by 2:

$\bf{2\text{B} \rightarrow 2\text{C} +2\text{D}}$ (2Δ $\text{H}_2$ ) -----(2)

This step converts all the B intermediates to 2C +2D. This means that the overall reaction at this stage is $\text{A} \rightarrow 2\text{C} +2\text{D}$ .

Reversing III. gives us a negative enthalpy change as such:

$\bf{2\text{D} \rightarrow \text{E}}$ (-Δ $\text{H}_3$ ) -----(3)

This step converts all the D intermediates formed from step (2) to E. This results in the overall equation of $\text{A} \rightarrow 2\text{C} +\text{E}$ , which is also the equation of interest.

Adding all three together:

$\text{A} \rightarrow 2\text{C}+\text{E}$ ( $\bf{\Delta\text{H}_1+2\Delta\text{H}_2-\Delta\text{H}_3 }$ )

Thus, the first option is the correct answer.

Supplementary:

To learn more about Hess's Law, do check out: brainly.com/question/26491956

4 0

2 years ago

What must be true of the net charge for any sample of sodium chloride

Ede4ka [16]

Answer:

Zero (0)

Explanation:

Since Na^+ has a charge of +1 and Cl^- has a charge of —1 in NaCl

Then the net = +1 —1 = 0

4 0

4 years ago

Read 2 more answers

Epsom salt, a common hydrate, has the formula shown below. If I measure out 125 g of epsom salt to add to my foot soak, what mas

tatiyna

Answer:

The answer to your question is 64.02 g of H₂O

Explanation:

Data

Mass of magnesium sulfate hepta hydrated = 125 g

Mass of water = ?

Process

1.- Calculate the molar mass of the salt and the molar mass of water

molar mass of MgSO₄ 7H₂O = 24 + 32 + 64 + 14 + 112 = 246 g

mass of H₂O = 2 + 16 = 18 g

2.- Use proportions to calculate the mass of water in the epsom salt

246 g MgSO₄ 7H₂O------------------------- 126 g of H₂O

125 g ------------------------- x

x = (125 x 126)/246

x = 15750/246

x = 64.02 g of H₂O

6 0

3 years ago