0.2701 moles of water were evaporated from the sample by the heating process
Mass of evaporating dish = 8.365 g
mass of dish + hydrate = 18.597 g
mass of hydrate = (mass of dish + hydrate) - mass of dish
hydrate = 18.597 - 8.365 = 10.232 g
Mass of dehydrated material = (mass of dish + dehydrate ) - mass of dish
dehydrated material = 18.735 - 8.365 = 5.37 g
Mass of water evaporated = hydrate - dehydrate
mass of water = 10.232 - 5.37 = 4.862 g
Molar mass of water = 18 gm/mol
no. of moles of water evaporated = mass / molecular mass
moles = 4.862/18 = 0.2701 moles
To learn more about mole click here:
brainly.com/question/29367909
#SPJ4
The elements atomic number, the number of protons in the necules
Answer:-
Carbon
[He] 2s2 2p2
1s2 2s2 2p2.
potassium
[Ar] 4s1.
1s2 2s2 2p6 3s2 3p6 4s1
Explanation:-
For writing the short form of the electronic configuration we look for the nearest noble gas with atomic number less than the element in question. We subtract the atomic number of that noble gas from the atomic number of the element in question.
The extra electrons we then assign normally starting with using the row after the noble gas ends. We write the name of that noble gas in [brackets] and then write the electronic configuration.
For carbon with Z = 6 the nearest noble gas is Helium. It has the atomic number 2. Subtracting 6 – 2 we get 4 electrons. Helium lies in 1st row. Starting with 2, we get 2s2 2p2.
So the short term electronic configuration is [He] 2s2 2p2
Similarly, for potassium with Z = 19 the nearest noble gas is Argon. It has the atomic number 18. Subtracting 19-18 we get 1 electron. Argon lies in 3rd row. Starting with 4, we get 4s1.
So the short electronic configuration is
[Ar] 4s1.
For long term electronic configuration we must write the electronic configuration of the noble gas as well.
So for Carbon it is 1s2 2s2 2p2.
For potassium it is 1s2 2s2 2p6 3s2 3p6 4s1
Answer:
Factors affecting a system in equilibrium are;
- concentration
- temperature
- pressure
Explanation:
A chemical equilibrium occurs when there is a proportion in mixtures of reactants and products.
For concentration, where some of the reactants are removed from an equilibrium reaction, the contents in the product side will be unbalanced thus the system will not be equilibrium and according to the Le Chatelier's principle, a system will shift in a manner to return balance in the reaction.
In temperature, in endothermic reactions, energy is considered as a reactant where as in exothermic reactions, energy is considered as a product.In exothermic reactions increase in temperature increases the reaction causing unbalanced reaction. A decrease in temperature causes a backward reaction which is endothermic
Increase in pressure causes the equilibrium to shift to the side of reaction with fewer moles of the reacting gas, where as a decrease in pressure forces the equilibrium to shift to the side of reaction with more moles of gas.
