Question

an element reacts with oxygen to give a compound with a high melting point. This compound is also soluble in water. The element is likely to be
a. calcium
b. carbon
c. silicon
d. Iron

Answer 1

Calcium.
Calcium Oxide is formed when Calcium reacts with Oxygen.

But In certain cases , Silicon Dioxide may also be possible(Bcoz its solubility depends on its crystalline structure.)


Hope that helps.

Answer 2

As per the given condition, the element is identified as Calcium. Thus option A is the correct answer.

Explanation:

• To solve such type of question, the reaction of the given elements with oxygen and the melting point of the product obtained must be identified.
• Accordingly, the reaction of oxygen with calcium, Carbon, Silicon and Iron is as follows:

$2Ca+O_2\rightarrow 2CaO$

$C+O_2\rightarrow CO_2$

$Si+O_2\rightarrow SiO_2$

$2Fe+2O_2\rightarrow Fe_2O_4$

• The melting points of the obtained products are as follows:

CaO - 2614°C

$CO_2$ - -56°C

$SiO_2$ - 1650°C

$Fe_2O_4$ - 1597°C

• From the above value, due to the high melting point value, the element is identified as calcium.

Learn more about such concept

Give reasons for the following observations:

a) Ionic compounds in general have high melting and boiling points.

b) Highly reactive metals cannot be obtained from their oxides by heating them with carbon.

c) Copper vessels get a green coat when left exposed to air in the rainy season.

https://brainly.in/question/2266211

What are the Properties of :

Metal.

Non Metals.

Metalliods.

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