Answer is: Zn + Cu2+ → Zn2+ + Cu.
In this chemical reaction, there is transfer of electrons from zinc (Zn) to copper (Cu). Zinc change oxidation number from 0 to +2 (lost electrons) and copper change oxidation number from +2 to 0 (gain electrons).
Oxidation half reaction: Zn⁰ → Zn²⁺ + 2e⁻.
Reduction half reaction: Cu²⁺ + 2e⁻ → Cu⁰.
In other chemical reactions, there is no change of oxidation number of elements.
First, We have to write the equation for neutralization:
Ba(OH)2 + 2HCl → BaCl2 + 2H2O
so, from the equation of neutralization, we can get the ratio between Ba(OH)2 and HCl. Ba(OH)2 : HCl = 1:2
- We have to get the no.of moles of Ba(OH)2 to do the neutralization as we have 25.9ml of 3.4 x 10^-3 M Ba(OH)2.
So no.of moles of Ba(OH)2 = (25.9ml/1000) * 3.4x10^-3 = 8.8 x 10^-5 mol
and when Ba(OH)2 : HCl = 1: 2
So the no.of moles of HCl = 2 * ( 8.8x10^-5) = 1.76 x 10^-4 mol
So when we have 1.76X10^-4 Mol in 16.6 ml (and we need to get it per liter)
∴ the molarity = no.of moles / mass weight
= (1.76 x 10^-4 / 16.6ml)* (1000ml/L) = 0.0106 M Hcl
Yes, the crystals will have more time to form and therefore are more likely to be larger compared to one that is cooled quickly.
The answer is 546K. If you need the answer in degrees Celsius you subtract 273 from 546 and get 273 degrees Celsius. I included how I got the answer in the photo below. Hope this helps!
When the formation of a substance is negative, it means that it releases heat to the surroundings. When
it releases heat to the surroundings, the reaction is exothermic. When it absorbs heat from the surroundings, the reaction is endothermic.
