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3 years ago

A solution of salt water is boiled. The water evaporates and solid salt remains. Which statement is true?

Chemistry

2 answers:

astraxan [27]3 years ago

8 0

Answer is: C. The salt and the water have both undergone physical changes.

The salt and the water make a homogeneous mixture (the same proportions of its components throughout any given sample).

A physical change occurs when a substance changes phase.

Boiling is a physical change (process), the same substance is present before and after the change, so chemical bonds and melting point of the substance are not changed.

Chemical change is when new substances are formed, the atoms are rearranged and the reaction is followed by an energy change.

kow [346]3 years ago

5 0

The answer would be C.

The salt and the water have both undergone physical changes.

Hope this helps!

You might be interested in

What type of nuclear reactions do all current reactors use

emmasim [6.3K]

Answer:

Nuclear fission

Explanation:

All nuclear reactors in operation are based on the principle of nuclear fission of Uranium nuclide to produce energy. These is produced is being controlled and is used in heating water to steam. The steam is then harnessed to drive or power steam turbines which is used for the generation of electricity.

8 0

3 years ago

A scientist measures the standard enthalpy change for the following reaction to be 67.9 kJ:

bekas [8.4K]

Answer: The standard enthalpy of formation of $H_2O(g)$ is -252.1 kJ/mol.

Explanation:

The balanced chemical reaction is,

$Fe_2O_3(s)+3H_2(g)\rightarrow 2Fe(s)+3H_2O(g)$

The expression for enthalpy change is,

$\Delta H=[n\times H_f_{products}]-[n\times H_f_{reactantss}]$

Putting the values we get :

$\Delta H=[2\times H_f{Fe}+3\times H_f{H_2O}]-[1\times H_f{Fe_2O_3}+3\times H_f{H_2}]$

$67.9kJ=[(2\times 0)+(3\times H_f{H_2O})]-[(1\times -824.2kJ/mol)+3\times 0kJ/mol)]$

$H_f{H_2O}=-252.1kJ/mol$

Thus standard enthalpy of formation of $H_2O(g)$ is -252.1 kJ/mol.

3 0

2 years ago

1. Una onda tiene una longitud de onda de 2 metros y una frecuencia de 1.5 Hz. ¿Cuál es su velocidad?

IrinaVladis [17]

Answer:

3 m/s

Explanation:

▲

usando la fórmula velocidad = frecuencia multiplicada por la longitud de onda.

v = (1.5)(2)

v= 3 m/s

6 0

3 years ago

If the value for ΔS is postive, and the value for ΔH is negative, thr reaction will be

dmitriy555 [2]

It follows that the reaction is spontaneous at high temperatures Option A.

The term ΔS is referred to as the change in the entropy of the system. Now recall that entropy is defined as the degree of disorderliness in a system. If a system is highly disorderly then it means that it has a high entropy. Also, ΔH has to do with the heat change that accompanies a reaction.

We know that both the entropy and the heat change can both either be positive or negative. Now we know that the equation ΔG = ΔH - TΔS can be used to ascertain whether or not a reaction will be spontaneous. If the result is negative, then the reaction will be spontaneous.

As such, when then it follows that the reaction is spontaneous at high temperatures Option A.

Learn more about spontaneous reaction:brainly.com/question/13790391

#SPJ1

6 0

1 year ago

What is the solubility of MgCO₃ in a solution that contains 0.080 M Mg²⁺ ions? (Ksp of MgCO₃ is 3.5 × 10⁻⁸)

Alchen [17]

Answer: 4.4 x 10^-7

Explanation:

The dissociation equation for this reaction is:

MgCO3 (s) → Mg+2 (aq) + CO3-2 (aq)

$\text { So, } k_{s p}=(x+0.08) x$ (Here 0.08 >>> x )

$\begin{aligned}\Rightarrow 3.5 \times 10^{-8} &=0.08 \times x \\\Rightarrow x &=\frac{3.5}{0.08} \times 10^{-8} \\&=4.37 \times 10^{-7} \\\Rightarrow x & \approx 4.4 \times 10^{-7} \mathrm{~M}\end{aligned}$

So the solubility MgCO₃ in a solution that containing 0.080 M Mg²⁺ is 4.4 x 10^-7

7 0

2 years ago