Answer:
Explanation:B ice melting is a phiyscal change and the mass of the substance remains the same
Explanation:
21. The given molecule for cracking is tetradecane.
On cracking it forms one mole of decane (C10H22) and two moles of ethene gas.
The chemical equation is shown below:

22. The essential condition for the formation of an ester is the reaction of alcohol and acid in presence of concentrated sulfuric acid.
Thus among the given options, the first option is the correct one.
23. Isomers of butanol are shown below:
It is 2-butanol.
The position of -OH group changes to the second carbon.
Molar mass SiO2 = 28 + 32 = 60
<span>so moles sand = 3.4 x 10-7 / 60</span>
The correct answer to the question is 25 percent by mass
Answer:
- <u><em>You should expect that the ionic bond in LiBr is stronger than the bond in KBr.</em></u>
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Explanation:
The<em> ionic bonds</em> are formed by the electrostatic attraction between the ions, cations and anions.
In KBr the cation is K⁺ and the anion is Br⁻.
In LiBr the cation is Li⁺ and the anion is Br⁻.
You must expect that the bond strength depends mainly on the charges present on each ion and the distance between them.
Nevertheless, the effect of the distance between the radius dominate the trendency of the bond strength, which makes that the ionic strength trend be related to the ionic radius trend.
Lithium is a smaller ion than Potassium (both are in the same group and Lithium is above Potassium).
Thus, you should expect that the Li ion is closer to the Br ion than what the K ion is to the Br ion and expect that the bond between a Li ion and the Br ion be stronger than the bond between the K ion and the Br ion.