Ask question

Ask question

All categories

3 years ago

15

A sample of metal is heated until it melts and begins to glow red. When it cools, it appears the same color as it did before it

was heated. This is evidence that a chemical reaction occurred. is it true or false

1 answer:

frosja888 [35]3 years ago

8 0

Answer:

Explanation:

trueeeeeeeeeeeeeeeeeeeeeeeeeee

You might be interested in

What is kinetic energy?

Natali5045456 [20]

Answer:

<h3>D energy of motion</h3>

Explanation:

Kinetic energy is the energy present in mass in motion

3 0

3 years ago

Fe(s) + CuSO4(aq) <===> Cu(s) + FeSO4(aq)

Ludmilka [50]

Answer : The original concentration of copper (II) sulfate in the sample is, $5.6\times 10^{-1}g/L$

Explanation :

Molar mass of Cu = 63.5 g/mol

First we have to calculate the number of moles of Cu.

Number of moles of Cu = $\frac{\text{Mass of Cu}}{\text{Molar mass of Cu}}=\frac{89\times 10^{-3}g}{63.5g/mol}=1.40\times 10^{-3}mole$

Now we have to calculate the number of moles of $CuSO_4$

Number of moles of Cu = Number of moles of $CuSO_4$

Number of moles of $CuSO_4$ = $1.40\times 10^{-3}mole$

Now we have to calculate the molarity of $CuSO_4$

$\text{Molarity}=\frac{\text{Moles of }CuSO_4\times 1000}{\text{Volume of solution (in mL)}}$

Now put all the given values in this formula, we get:

$\text{Molarity}=\frac{1.40\times 10^{-3}mole\times 1000}{400.mL}=0.0035M$

To change mol/L into g/L, we need to multiply it with molar mass of $CuSO_4$

Molar mass of $CuSO_4$ = 159.609 g/mL

Concentration in g/L = $0.0035M\times 159.609g/mol=0.5586g/L\approx 5.6\times 10^{-1}g/L$

Thus, the original concentration of copper (II) sulfate in the sample is, $5.6\times 10^{-1}g/L$

3 0

2 years ago

What are limitations of a conclusion? I am doing a science lab write-up and under the conclusion it asks for limitations of the

enyata [817]

I believe it means the imitations on what you did what were you not able to do to the object. I'm not too sure but I believe that's what it means. I hope I was able to help

5 0

3 years ago

What are some visible signs of an acid-base reaction?

marta [7]

I think one of the signs is <span>water and salt are formed

</span>

6 0

3 years ago

Where is the ion charge located in the isotope symbol

Juliette [100K]

The ion charge located in the isotope symbol on the top right corner. <span>The number part of an </span>isotope's<span> name is the Mass Number (P + N). A negatively</span>charged ion<span> (anion) will have more Electrons than Protons. Cl 1- has one more electron than proton; 18 electrons, 17 protons. That's why its </span>charge<span> is 1-.</span>

3 0

3 years ago