The freezing point depression of water is 1.86°C/m.kg
<span>K2S dissociates: </span>
<span>K2S ↔ 2K+ + S 2- </span>
<span>1mol K2S will produce 3 mol of ions. </span>
<span>Therefore in the freezing point equation: i = 3 </span>
<span>Depression of freezing point = Kf * i* m </span>
<span>Depression of freezing point = 1.86*3*0.195 </span>
<span>Depression of freezing point = 1.088°C </span>
<span>The solution will freeze at - 1.088°C </span>
Answer:
See explanation
Explanation:
The law of conservation of mass states that mass can neither be created nor destroyed. This implies that in a chemical reaction, we can only have the same number of atoms of each element on both sides of the reaction equation.
If we write 4Fe2S3 it means that we have;
4 * 2 = 8 atoms of Fe
4 * 3 = 12 atoms of S
8 + 12 = 20 atoms in all
Answer is (b) , because a chemical change happened
Answer:
1.) AgNO₃
2.) 0.563 moles AgBr
Explanation:
The limiting reagent is the reagent that is used up completely during a reaction. It can be identified by calculating which reactant produces the smallest amount of product. This can be done by determining the number of moles of each reagent (via molarity conversion). and then converting it to moles of the product (via mole-to-mole ratio).
AgNO₃ (aq) + KBr (aq) ---> AgBr (s) + KNO₃ (aq)
Molarity (M) = moles / liters
100 mL = 1 L
AgNO₃
45.0 mL / 100 = 45.0 L
1.25 M = ? moles / 0.450 L
? moles = 0.563 moles
KBr
75.0 mL / 100 = 0.750 L
0.800 M = ? moles / 0.750 L
? moles = 0.600 moles
In this case, there is no need to use the mole-to-mole ratio because all of the coefficients are one in the reaction (the amount of the limiting reagent used is the same amount of product produced). Since AgNO₃ produces the smaller amount of product, it is the limiting reagent.
