Answer:
4.56×10^-10
Explanation:
Co(OH)2(s)<------->Co^2+(aq) + 2OH^-(aq)
Co^2+(aq) + 6NH3(aq) ---------->[Co(NH3)6]^2+(aq)
Overall equation:
Co(OH)2(s)+ 6NH3(aq) ---------->[Co(NH3)6]^2+(aq) + 2OH^-(aq)
The increased solubility of the cobalt salt in the presence of ammonia is as a result of the formation of the hexammine cobalt II complex shown above.
Knet= Ksp×Kf
Ksp of Co(OH)2= 5.92 × 10^-15.
Kf= 7.7 x 10^4
Knet= 5.92 × 10^-15 × 7.7 x 10^4
Knet= 4.56×10^-10
Note Knet is the equilibrium constant of the overall reaction.
Topaz and quartz
Explanation:
Topaz and quartz are minerals that will scratch feldspars but will not scratch corundum. Corundum is one of the hardest substance based on moh's scale.
The hardness of a mineral is its resistance to deformation. A mineral is harder than another if it can scratch it.
The moh's scale of hardness list minerals in the order of their hardness:
- Talc
- Gypsum
- Calcite
- Fluorite
- Apatite
- Orthoclase
- Quartz
- Topaz
- Corundum
- Diamond
Diamond is the hardest and talc is the softest.
Orthoclase is a feldspar.
learn more:
Rocks as mineral aggregates brainly.com/question/6568161
Silicate minerals brainly.com/question/4772323
#learnwithBrainly
3.50g H2:
3.50g H2 x 1 mol H2 / 2(1.01gH2)= 1.7675mol H2
- the grams cancel out
- the answer rounded up would be: 2 mol H2
Answer:
13.4%
Explanation:
Take the molar mass (26.98) of Al x 2 because there are 2 moles in the given compound. Divide this number by the total molar mass of the compound (401.9) this gives you .134. To get a percentage mulitply by 100 for 13.4%.
[(26.98 x 2)/401.9] x 100 =13.4
All you have to do is multiply the amount of moles by 6.02x10^23 which is Avagadro's number.
