We have to know the molarity of solution obtained when 5.71 g of Na₂CO₃.10 H₂O is dissolved in water and made up to 250 cm³ solution.
The molarity of solution obtained when 5.71 g of sodium carbonate-10-water (Na₂CO₃.10 H₂O) is dissolved in water and made up to 250.0 cm^3 solutionis: (A) 0.08 mol dm⁻³
The molarit y of solution means the number of moles of solute present in one litre of solution. Here solute is Na₂CO₃.10 H₂O and solvent is water. Volume of solution is 250 cm³.
Molar mass of Na₂CO₃.10 H₂O is 286 grams which means mass of one mole of Na₂CO₃.10 H₂O is 286 grams.
5.71 grams of Na₂CO₃.10 H₂O is equal to
= 0.0199 moles of Na₂CO₃.10 H₂O. So, 0.0199 moles of Na₂CO₃.10 H₂O present in 250 cm³ volume of solution.
Hence, number of moles of Na₂CO₃.10 H₂O present in one litre (equal to 1000 cm³) of solution is
= 0.0796 moles. So, the molarity of the solution is 0.0796 mol/dm³ ≅ 0.08 mol/dm³
Answer:
31.24 kJ
Explanation:
- SiO₂(g) + 3C(s) → SiC(s) + 2CO(g) ΔH° = 624.7 kJ/mol
First we <u>convert 3.00 grams of SiO₂ to moles</u>, using its <em>molar mass</em>:
- 3.00 g SiO₂ ÷ 60.08 g/mol = 0.05 mol
Now we <u>calculate the heat absorbed</u>, using the <em>given ΔH°</em>:
If the complete reaction of 1 mol of SiO₂ absorbs 624.7 kJ, then with 0.05 mol:
- 0.05 mol * 624.7 kJ/mol = 31.24 kJ of heat would be absorbed.
+
⇔
Decreasing the temperature of the reaction,the reaction shifts forward.
The explanation is given below.
Explanation:
If the temperature of the reaction mixture is increased,then the equilibrium will shift to decrease the temperature.
If the temperature of the reaction mixture is decreased,then the equilibrium will shift to increase the temperature.
During the formation of the ammonia,it gives off heat.So it is an exothermic reaction.
+
⇔
A decrease in the temperature favors the reaction that is exothermic (the forward reaction)because it produces energy.Therefore,if the temperature is decreased,the yield of the ammonia increases.
<em>Therefore if the temperature is increased,the reaction shifts forward and the yield of the ammonia increases and it is an exothermic reaction.</em>
Answer:
AuCl
Explanation:
Given parameters:
Mass of Gold = 2.6444g
Mass of Chlorine = 0.476g
Unknown:
Empirical formula = ?
Solution:
Empirical formula is the simplest formula of a compound. Here is the way of determining this formula.
Elements Au Cl
Mass 2.6444 0.476
Molar mass 197 35.5
Number of moles 2.6444/197 0.476/35.5
0.013 0.013
Divide by the
smallest 0.013/0.013 0.013/0.013
1 1
The empirical formula of the compound is AuCl
Jim, because he ran a greater distance in the same time :)
By the way, this is a maths question