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3 years ago

Why does ice get colder when you melt it?

Chemistry

1 answer:

galina1969 [7]3 years ago

8 0

It doesn't?

Heat transfers from hot objects to cold objects and for ice to melt it has to increase the temperature.

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How is a planet different from a moon? (2 points)

earnstyle [38]

Answer:

Explanation:

I just know.

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3 years ago

In order to design an experiment, you need a ____ about the scientific question you are trying to answer. A. decision B. procedu

kolbaska11 [484]

The correct answer is option C, that is, hypothesis.

The hypothesis is the starting building block in the scientific method. It is also illustrated as an educated guess, based on previous observation and knowledge. A hypothesis refers to a recommended solution for an unexplained event, which does not fit into the present accepted scientific theory.

The fundamental concept of a hypothesis is that there is no pre-determined result. For a hypothesis to be considered as scientific hypothesis, it has to be something, which can be refuted or supported via carefully crafted observation or experimentation.

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3 years ago

Make the following conversion. 120 mL = _____ cm³ 12.0 1200 120 1.20

Lina20 [59]

The correct answer would be 120.

4 0

3 years ago

Read 2 more answers

Be sure to answer all parts. What is the [H3O+] and the pH of a buffer that consists of 0.26 M HNO2 and 0.89 M KNO2? (K, of HNO2

Aleksandr-060686 [28]

Answer : The $H_3O^+$ ion concentration is, $1.12\times 10^{-3}M$ and the pH of a buffer is, 2.95

Explanation : Given,

$K_a=7.1\times 10^{-4}$

Concentration of $HNO_2$ (weak acid)= 0.26 M

Concentration of $KNO_2$ (conjugate base or salt)= 0.89 M

First we have to calculate the value of $pK_a$ .

The expression used for the calculation of $pK_a$ is,

$pK_a=-\log (K_a)$

Now put the value of $K_a$ in this expression, we get:

$pK_a=-\log (7.1\times 10^{-4})$

$pK_a=4-\log (7.1)$

$pK_a=3.15$

Now we have to calculate the pH of the solution.

Using Henderson Hesselbach equation :

$pH=pK_a+\log \frac{[Salt]}{[Acid]}$

$pH=pK_a+\log \frac{[KNO_2]}{[HNO_2]}$

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

$pH=3.15+\log (\frac{0.89}{0.26})$

$pH=2.95$

The pH of a buffer is, 2.95

Now we have to calculate the $H_3O^+$ ion concentration.

$pH=-\log [H_3O^+]$

$2.95=-\log [H_3O^+]$

$[H_3O^+]=1.12\times 10^{-3}M$

The $H_3O^+$ ion concentration is, $1.12\times 10^{-3}M$

4 0

3 years ago

I have seven energy levels, but only 1 valence eletron?

Olenka [21]

Answer:

Francium (Fr)

Explanation:

Looking at the periodic table, Francium has 7 energy levels as it is in the 7th Period and is in the 1st Group (meaning it has one electron in the outermost shell) which suggests that it has one valence electron.

Hope this helps and be sure to have a wonderful time ahead at Brainly! :D

3 0

2 years ago