Answer:
Na₂CO₃.2H₂O
Explanation:
For the hydrated compound, let us denote is by Na₂CO₃.xH₂O
The unknown is the value of x which is the amount of water of crystallisation.
Given values:
Starting mass of hydrate i.e Na₂CO₃.xH₂O = 4.31g
Mass after heating (Na₂CO₃) = 3.22g
Mass of the water of crystallisation = (4.31-3.22)g = 1.09g
To determine the integer x, we find the number of moles of the anhydrous Na₂CO₃ and that of the water of crystallisation:
Number of moles = 
Molar mass of Na₂CO₃ =[(23x2) + 12 + (16x3)] = 106gmol⁻¹
Molar mass of H₂O = [(1x2) + (16)] = 18gmol⁻¹
Number of moles of Na₂CO₃ = 
= 0.03mole
Number of moles of H₂O = 
= 0.06mole
From the obtained number of moles:
Na₂CO₃ H₂O
0.03 0.06
Simplest
Ratio 0.03/0.03 0.03/0.06
1 2
Therefore, x = 2
The answers to this question is b, I did this on Plato
The answer is to heat the water up to increase the rate that which it dissolves
The question is incomplete, here is the complete question:
There are two steps in the usual industrial preparation of acrylic acid, the immediate precursor of several useful plastics. In the first step, calcium carbide and water react to form acetylene and calcium hydroxide:
In the second step, acetylene, carbon dioxide and water react to form acrylic acid:
Write the net chemical equation for the production of acrylic acid from calcium carbide, water and carbon dioxide. Be sure your equation is balanced.
<u>Answer:</u> The net chemical equation is written below.
<u>Explanation:</u>
The intermediate balanced chemical reaction are:
(1) ( × 6 )
(2)
To omit acetylene from the net chemical reaction, we multiply Equation (1) by 6.
<u>Equation 1:</u> 
<u>Equation 2:</u>
<u>Net chemical equation:</u> 
Hence, the net chemical equation is written above.
Answer:
The equation that correctly describes the decay is :
Ra -----> 
Rn + 
He
Explanation:
When the solid radium start decaying in order to form the radon gas, it starts losing two protons with one neutron. The two neutron as well as one proton together forms an alpha particle, hence a type of radiation is formed. Also we know that radon itself is radioactive as it also leads to the decay, after that it loses an alpha particle and also form an element called as polonium. Radium being the most stable form of isotope, radium 226, also holds a half life of 1600 years. It will decay into radon 222 through the alpha decay or can also lead 212 by ejecting a carbon 14 nucleus.
