the mass of potassium iodide is 0.360 g
calculation
step 1: write the balanced molecular equation
Pb(NO3)2 (aq) + 2 Ki (s)→ Pbi2(s) + 2KNO3
step 2 ; calculate the moles of Pbi2
moles = mass /molar mass
= 0.500 g / 461 .0 g/mol =0.0011 moles
step 3: use the mole ratio to calculate the moles of Ki
Ki: Pbi2 is 2:1 therefore the moles of ki = 0.0011 x 2/1 = 0.0022 moles
step 4 : find the mass of Ki
mass= moles x molar mass
=0.0022 moles x 166g/mol =0.365 g which is approximate 0.360 g
1
Explanation:
This problem deals with balancing of chemical equations.
Every chemical equations obey the law of conservation of matter which states that "in chemical reactions, matter is usually conserved and are not produced, they are simply recombined".
Equation of reaction:
BaO₂ + H₂SO₄ ⇒ H₂O₂ + BaSO₄
Let us use a mathematical approach to balance this equation by setting up simple algebraic equations:
aBaO₂ + bH₂SO₄ ⇒ cH₂O₂ + dBaSO₄
a, b, c and d are the number of moles that will balance the equation;
Conserving Ba: a = d
O: 2a + 4b = 2c + 4d
H: 2b = 2c
S: b = d
now let a = 1
d = 1
b = 1
c = 1
we see that the equation is already balanced
learn more:
Balanced equation brainly.com/question/5297242
#learnwithBrainly
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Answer:</h3>
812 kPa
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Explanation:</h3>
- According to Boyle's law pressure and volume of a fixed mass are inversely proportional at constant absolute temperature.
- Mathematically,
At varying pressure and volume;
P1V1=P2V2
In this case;
Initial volume, V1 = 2.0 L
Initial pressure, P1 = 101.5 kPa
Final volume, V1 = 0.25 L
We are required to determine the new pressure;
Replacing the known variables with the values;
= 812 kPa
Thus, the pressure of air inside the balloon after squeezing is 812 kPa
It must absorb energy in the form of for example heat which gives it the energy required to become excited
hope that helps
