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3 years ago

In a science experiment, Javi concludes that a chemical reaction has occurred. What evidence would support this conclusion?

Chemistry

2 answers:

Naily [24]3 years ago

8 0

Answer:

B) a substance's color and odor changed Explanation: A signal that a chemical change has occurred is when its odor (its smell) or its appearance has changed.

Romashka [77]3 years ago

6 0

Answer:

that correct answer is The product is not poisonous or odorous like chlorine, and it’s no longer a metal like sodium. It does not have the same properties as either reactant. Also, the white “dust” in the video indicates that a reaction has taken place.

Explanation:

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How is geothermal produced

soldier1979 [14.2K]

The steam rotates a turbine that activates a generator, which produces electricity. Many power plants still use fossil fuels to boil water for steam. Geothermal power plants, however, use steam produced from reservoirs of hot water found a couple of miles or more below the Earth's surface.

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3 years ago

Read 2 more answers

How do you know that volume of a diamond is 15.1g

marshall27 [118]

Answer:

Density = mass / volume,

therefore volume = mass / density. Note that 1 mL = 1 cubic centimeter.

Explanation:

Volume = 15.1g / 3.52g/mL = 4.3mL = 4.3 cubic centimeters.

then a diamond has a density of 3.52 g/mL.

4 0

4 years ago

Given that Δ H ∘ f [ Br ( g ) ] = 111.9 kJ ⋅ mol − 1 Δ H ∘ f [ C ( g ) ] = 716.7 kJ ⋅ mol − 1 Δ H ∘ f [ CBr 4 ( g ) ] = 29.4 kJ

JulsSmile [24]

Answer:

283.725 kJ ⋅ mol − 1

Explanation:

C(s) + 2Br2(g) ⇒ CBr4(g) , Δ H ∘ = 29.4 kJ ⋅ mol − 1

$\frac{1}{2}$ Br2(g) ⇒ Br(g) , Δ H ∘ = 111.9 kJ ⋅ mol − 1

C(s) ⇒ C(g) , Δ H ∘ = 716.7 kJ ⋅ mol − 1

4*eqn(2) + eqn(3) ⇒ 2Br2(g) + C(s) ⇒ 4 Br(g) + C(g) , Δ H ∘ = 1164.3 kJ ⋅ mol − 1

eqn(1) - eqn(4) ⇒ 4 Br(g) + C(g) ⇒ CBr4(g) , Δ H ∘ = -1134.9 kJ ⋅ mol − 1

so,

average bond enthalpy is $\frac{1134.9}{4}$ = 283.725 kJ ⋅ mol − 1

4 0

3 years ago

A solution is prepared by adding 0.0231moles of H3O+ ions to 3.33L of water. What is the pH of this solution

MrMuchimi

Answer:

2.15

Explanation:

For this question, we have to remember the pH formula:

$pH~=~-Log[H_3O^+]$

By definition, the pH value is calculated when we do the -Log of the concentration of the hydronium ions ( $H_3O^+$ ). So, the next step is the calculation of the concentration of the hydronium ions. For this, we have to use the molarity formula: