explain the following-KOH is more basic than NaOH,
BeSO4 is water soluble,
TlCl3+ is less stable than TlCl,
SnCl2 is more stable than SnCl4, PbCl2 is more stable than PbCl4

Dear student,
Kindly find the answer in following links:
www.meritnation.com/ask-answer/question/which-is-stronger-base-naoh-and-koh-explain/chemistry/7037106

www.meritnation.com/ask-answer/question/why-tlclis-more-stable-than-tlcl3/chemical-bonding-and-molecular-structure/8367137​
www.meritnation.com/ask-answer/question/pbcl4-is-less-stable-than-sncl4-but-pbcl2-is-more-stable-tha/chemistry/6581980​                                                                                                                                                              Beryllium sulphate is soluble in water because of its high hydration energy & low lattice energy(due to small Be²⁺ cation and large SO₄^2- anion).Solubility is directly proportional to hydration energy and inversely proportional to lattice energy.

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