Question
Question: According to CRC’s, the melting point of cadmium bromide is 868\(^{o}C\) . Which of the following eq...
According to CRC’s, the melting point of cadmium bromide is 868oC . Which of the following equations best describes what occurs when cadmium bromide is heated to 868oC ?
A. CdBr(s)→CdBr(l)
B. CdBr2(s)→CdBr2(l)
C. CdBr2(s)→Cd(s)+Br2(g)
D. CdBr2(s)→Cd2+(aq)+2Br−(aq)
Solution
Melting point of a substance means at a certain temperature, the substance is going to change from one phase to another phase. Means at melting point one substance changes its phase from solid phase to liquid phase.
Complete step by step answer:
- In the question it is asked to find which of the given chemical equation suits when cadmium bromide is heated to 868oC .
- And also it is given that the melting point of cadmium bromide is 868oC .
- We know that at melting point only chemicals or substances change from one phase to another.
- Means cadmium bromide should change from one phase to another phase at 868oC .
- Generally at room temperature Cadmium bromide is in solid state.
- At 868oC cadmium bromide changes from solid state to liquid state.
- Means we have to choose an option where only changing of phase or state from solid to liquid is mentioned.
- The chemical formula of cadmium bromide is CdBr2 .
- By observing all the options, option B only explains the changing of cadmium bromide from solid state to liquid state.
CdBr2(s)→CdBr2(l)
So, the correct answer is “Option B”.
Note: Don’t be confused between melting point and boiling point. Both are not the same. At melting point a solid substance converts to liquid substance and at boiling point a liquid substance converts to gaseous substance.