Heat energy is needed for evaporation to happen.
2, 4, 1
Explanation:
We have the following chemical reaction:
Ag₂O → Ag + O₂
To balance the chemical equation the number of atoms of each element entering the reaction have to be equal to the number of atoms of each element leaving the reaction, in order to conserve the mass.
So the balanced chemical equation is:
2 Ag₂O → 4 Ag + O₂
Learn more about:
balancing chemical equations
brainly.com/question/14112113
brainly.com/question/14187530
#learnwithBrainly
If you'd like the full working, here it is:
I calculated this by using the formula triangle.
Mass
Number Formula
Of moles Mass
To calculate the number if moles in a substance, you need to divide the Mass by the Formula mass. You get the formula mass by adding the atomic masses of the elements in the compound together. In this situation, H2O, it would be two hydrogen molecules plus one oxygen molecule which is 2 + 16. This is because the atomic mass of Hydrogen is 1 and the atomic mass of Oxygen is 16.
Now that we have the Formula mass we can go ahead and do the calculation since we already have the Mass. You do as follows:
Mass divided by Formula mass which is in this case - 25 divided by 18
By doing this calculation you will get the answer which is 1.38 moles which can be rounded to 1.4
Hope this helps :)
Answer:
Pb(NO3)2 + 2NaCl = 2NaNO3 + PbCl2
All of them are properties of compounds except III.
for I, compounds are chemically combined together, so to separate them, we must use chemical methods like electrolysis or applying heat. These requires large amount of energy.
For II, they're always fixed. For example, in water (H2O), the ratio of hydrogen and oxygen is always 1:8 in mass. If there's some extra added, the substance becomes mixture instead of compounds.
For IV, after you chemically combined elements or compounds together, their properties are completely different. For example, iron can be attracted to magnets, but iron II sulphide does not.
