Question

So i have my chemistry exam next week and this is a question from the practice test. I am wondering more of the how/why for this question than just the answer? How do you tell what is soluable and what isn't how to know what the reaction is gonna be? Is there any easier way to think about this than memorizing the solubility chart. And even with he chart memorized... how do i answer a question like this, am i looking for slightly soluble?

When aqueous solutions of ________ are mixed, a precipitate forms.

A) NiCl2 and AgNO3

B) NaCl and KBr

C) K2SO4 and CrCl3

D) KOH and AgNO3

E) Li2CO3 and KCl

more questions I'm concerned about... again not looking for the answers just like how to go about understanding the solubility and reactions between substances?

Which of the following is an oxidation-reduction reaction? A) HCl (aq) + NaOH (aq) → H2O (l) + NaCl (aq) B) AgNO3 (aq) + HCl (aq) → AgCl (s) + HNO3 (aq) C) BaCl2 (aq) + Na2SO4 (aq) → BaSO4 (s) + 2NaCl2(aq) D) Mg (s) + 2AgNO3 (aq) → 2Ag (s) + Mg(NO3)2 (aq) E) H2CO3 (aq) + Ca(NO3)2 (aq) → 2HNO3 (aq) + CaCO3 (s)

4) The balanced reaction between aqueous nitric acid and aqueous strontium hydroxide is ________. A) 2HNO3 (aq) + Sr(OH)2 (aq) → 2H2O (l) + Sr(NO3)2 (aq) B) HNO3 (aq) + Sr(OH)2 (aq) → Sr(NO3)2 (aq) + H2 (g) C) HNO3 (aq) + Sr(OH)2 (aq) → H2O (l) + Sr(NO3)2 (aq) D) HNO3 (aq) + SrOH (aq) → H2O (l) + SrNO3 (aq) E) 2HNO3 (aq) + Sr(OH)2 (aq) → Sr(NO3)2(aq) + 2H2 (g)
5) In which reaction does the oxidation number of hydrogen change? A) HCl (aq) + NaOH (aq) → NaCl (aq) + H2O (l) B) 2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g) C) CaO (s) + H2O (l) → Ca(OH)2 (s) D) 2HClO4 (aq) + CaCO3 (s) → Ca(ClO4)2 (aq) + H2O (l) + CO2 (g) E) SO2 (g) + H2O (l) → H2SO3 (aq)

Answer 1

Answer 1

You find that which salt in less soluble in water means more covalent character by using fajans rule that find that cation metal have small size and haigh charge , it is usually for main group elements metal

For anion you see that big size and more negative charge

And also use Solubility of ion product is more than Solubility product constant (Ksp) means which ion product more is going to opt.

Not solubility and ksp value given in exam always

Answer 2

The following is an oxidation-reduction reaction)

(D) Mg (s) + 2AgNO3 (aq) → 2Ag (s) + Mg(NO3)2 (aq)

Because Mg is going to oxidation and gointo +2 oxidation state and Ag is going to reduction menas Ag+ is going to zero oxidation state means reduce

All other not changing any oxidation state , so by calculation of oxidation of each element you find oxidation reduction reaction.

Answer 4

4) The balanced reaction between aqueous nitric acid and aqueous strontium hydroxide is ________.

2HNO3 (aq) + Sr(OH)2 (aq) → 2H2O (l) + Sr(NO3)2 (aq)

It done by count both side (reactant and product) each element type which reaction give equal number of different type of element is balance equation.

Answer 5

5) Reaction does the oxidation number of hydrogen change

2Na (s) + 2H2O (l) → 2NaOH (aq) + H2 (g)

By counting oxidation state of H here reactant side oxidation is +1

And product side zero oxidation state