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3 years ago

Is the temperature at which a substance melts the same as the temperature changes from a liquid to a solid

Chemistry

1 answer:

sasho [114]3 years ago

8 0

Answer:

No.

Explanation:

If the temperature changes a substance from it's original form, going from solid to liquid, then the temperature required to change it from a liquid to a solid are the opposite. For example, Ice is Water (H2O) in it's solid form. In order to freeze water into ice, the temperature must be very low. In order to melt the ice back into water, the temperature must be higher than the freezing point, but not too high or it will boil, making it a gaseous substance instead.

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3 years ago

The breeding of animals is necessary to produce

Aneli [31]

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3 years ago

What is the main point of mutation ? quick please !!

Ede4ka [16]

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Explanation:

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3 years ago

Read 2 more answers

Question 1 (True/False Worth 2 points) (04.03 LC) When Pb and AlCl3 react together, lead (Pb) can replace aluminum (Al) in the c

aivan3 [116]

Answer:

For 1: The correct answer is false.

For 2: The correct answer is $Na_3PO_4+3KOH\rightarrow 3NaOH + K_3PO_4$ , because K retains the same charge throughout the reaction.

For 3: The correct answer is $Zn+H_2SO_4\rightarrow ZnSO_4 + H_2$

For 4: The correct answer is a single replacement reaction takes place because sodium is more reactive than hydrogen.

For 5: The correct answer is False.

For 6: The correct answer is it is a single replacement reaction, and the cations in the two ionic compounds are different.

Explanation:

For 1:

This type or reaction is based on the reactivity series. If the metal which lies above in the series will replace the metal which lies below in the series easily.

From the reactivity table attached below, we know that lead lies below in the series to Aluminium and hence, it will not replace in the reaction.

$Pb+AlCl_3\rightarrow \text{No reaction}$

Hence, the correct answer is False.

For 2:

A balanced equation is defined as the equation in which there are same number of atoms present on the reactant side and the product side.

The balanced equation always follow Law of Conservation of Mass.

So, from the given options, the below equation is the balanced equation because K retains the same charge throughout the reaction.

$Na_3PO_4+3KOH\rightarrow 3NaOH + K_3PO_4$

For 3:

A single displacement reaction is a type of chemical reaction in which one element replaces another element in a chemical reaction. The element which is more reactive will replace the less less reactive element.

This is explained by reactivity series as the metal which lies above in the series will replace the metal which lies below in the series easily. From the given equations, the equation which is a type of single displacement reaction is:

$Zn+H_2SO_4\rightarrow ZnSO_4 + H_2$

$Ba(OH)_2+H_2SO_4\rightarrow BaSO_4 + 2H_2O$ : This equation is a type of double displacement reaction.

$2Mg+O_2\rightarrow 2MgO$ : This equation is a type of combination reaction.

$H_2O+CO_2\rightarrow H_2CO_3$ : This equation is a type of combination reaction.

For 4:

A single displacement reaction is a type of chemical reaction in which one element replaces another element in a chemical reaction.

$A+BC\rightarrow AC+B$

A double displacement reaction is a type of chemical reaction in which exchange of ins takes place.

$AB+CD\rightarrow AD+BC$

In the question, it is asked that sodium metal is reacting with water to produce hydrogen gas and sodium hydroxide. This reaction is a type of single displacement reaction because sodium is more reactive than hydrogen as shown in the reactivity series.

$2Na+2H_2O\rightarrow H_2+2NaOH$

For 5:

A single displacement reaction is a type of chemical reaction in which one element replaces another element in a chemical reaction. This reaction will not follow when an element replaces similar element.

Hence, the statement is False.

For 6:

For the reaction:

$\text{Metal + Ionic compound}\rightarrow \text{Metal + Ionic compound}$

It is a type single replacement reaction as the cations in the two ionic compounds are different.

For Example:

$3Na+AlCl_3\rightarrow 3NaCl+Al$

Where, Sodium and Aluminium are the cations and chlorine is an anion.

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3 years ago

Read 2 more answers