Answer:
Explanation:
1. Add the atomic mass of all the elements.
39+55.8+12+14= 120.8
2.Divide atomic mass of potassium by total atomic mass

2. Multiply by 100
%32.3
First, we write the balanced equation for this reaction:
2KI + Pb(NO₃)₂ → 2KNO₃ + PbI₂
From this equation, we see that there are 2 moles of potassium iodide required for each mole of lead (II) nitrate. Moreover, we may use the formula:
Moles = volume (in L) * molarity
We find the molar relation ship for KI : Pb(NO₃)₂ to be 2 : 1. So:
M₁V₁ = 2M₂V₂
V₁ = 2M₂V₂/M₁
V₁ = 2 * 0.112 * 0.155 / 0.2
V₁ = 0.1736 L
The volume required is 173.6 mL
Answer: A closed system, because energy can enter or leave the container, but the water molecules cannot
Explanation:
Open system: In this system energy and matter both have access to their surroundings beyond the boundaries of system. .
Closed system :In this type system only energy has an access to its surroundings beyond the boundaries of system but not matter.
Isolated system:In this type system exchange of both energy and matter are restricted to move outside the boundaries of system.
According to question, the system given is a closed system because energy is transferred from the burner to glass flask and from the glass flask to the water (matter). But water molecules are only getting condensed on the inside surface of the flask that is exchange of matter beyond the boundaries of the system is restricted. Hence, closed system ,A closed system, because energy can enter or leave the container, but the water molecules cannot.
20 g O2 x 1 mol O2/32 g O = 0.625 mol O2