Answer:
I'm not an expert at this, but I assume its mercury.
Answer:
Mass PbI2 = 18.19 grams
Explanation:
Step 1: Data given
Volume solution = 99.8 mL = 0.0998 L
mass % KI = 12.0 %
Density = 1.093 g/mL
Volume of the other solution = 96.7 mL = 0.967 L
mass % of Pb(NO3)2 = 14.0 %
Density = 1.134 g/mL
Step 2: The balanced equation
Pb(NO3)2(aq) + 2 KI(aq) ⇆ PbI2(s) + 2 KNO3(aq)
Step 3: Calculate mass
Mass = density * volume
Mass KI solution = 1.093 g/mL * 99.8 mL
Mass KI solution = 109.08 grams
Mass KI solution = 109.08 grams *0.12 = 13.09 grams
Mass of Pb(NO3)2 solution = 1.134 g/mL * 96.7 mL
Mass of Pb(NO3)2 solution = 109.66 grams
Mass of Pb(NO3)2 solution = 109.66 grams * 0.14 = 15.35 grams
Step 4: Calculate moles
Moles = mass / molar mass
Moles KI = 13.09 grams / 166.0 g/mol
Moles KI = 0.0789 moles
Moles Pb(NO3)2 = 15.35 grams / 331.2 g/mol
Moles Pb(NO3)2 = 0.0463 moles
Step 5: Calculate the limiting reactant
For 1 mol Pb(NO3)2 we need 2 moles KI to produce 1 mol PbI2 and 2 moles KNO3
Ki is the limiting reactant. It will completely be consumed ( 0.0789 moles). Pb(NO3)2 is in excess. There will react 0.0789/2 = 0.03945 moles. There will remain 0.0463 - 0.03945 = 0.00685 moles
Step 6: Calculate moles PbI2
For 1 mol Pb(NO3)2 we need 2 moles KI to produce 1 mol PbI2 and 2 moles KNO3
For 0.0789 moles KI we'll have 0.0789/2 = 0.03945 moles PbI2
Step 7: Calculate mass of PbI2
Mass PbI2 = moles PbI2 * molar mass PbI2
Mass PbI2 = 0.03945 moles * 461.01 g/mol
Mass PbI2 = 18.19 grams
Answer:
Explanation:
Hello,
In this case, we write the reaction again:
In such a way, the first thing we do is to compute the reacting moles of lead (II) nitrate and potassium iodide, by using the concentration, volumes, densities and molar masses, 331.2 g/mol and 166.0 g/mol respectively:
Next, as lead (II) nitrate and potassium iodide are in a 1:2 molar ratio, 0.04635 mol of lead (II) nitrate will completely react with the following moles of potassium nitrate:
But we only have 0.07885 moles, for that reason KI is the limiting reactant, so we compute the yielded grams of lead (II) iodide, whose molar mass is 461.01 g/mol, by using their 2:1 molar ratio:
Best regards.
Answer:
5.076 * 10 ⁻¹² M
Explanation:
molarity of a solution is given as -
Molarity (M) = ( w / m ) / V ( in L)
where ,
m = molecular mass ,
w = given mass ,
V = volume of solution ,
From the question ,
w = given mass of epinephrine = 0.00000093 g
V = 1 L
Since , the molecular mass of epinephrine = m = 183,204 g/mol
M = ?
In order to determine the molarity of epinephrine , the above formula is used , by putting the respected values ,
Molarity (M) = ( w / m ) / V ( in L)
M = ( 0.00000093 g / 183,204 g/mol ) / 1 L
M = 5.076 * 10 ⁻¹² M
Answer: Cao2
Explanation: the reason for this is because the chemical reactions on both sides should be equal and since the O has a 2 the O should have 2 on the other equation.
41.0 + 78.3 =
Ans: 1) 1.41
2) 119.3
While adding two numbers, the rule of significant figures requires that the number of decimal places in the final answer is equal to that of the term with the least decimal places
In the given examples:
1) 0.09 - has 2 decimal places
1.324- has 3 decimal places
Sum = 0.09 + 1.324 = 1.414
Round off to 2 decimal places = 1.41
2) 41.0 - has 1 decimal place
78.3- has 1 decimal place
Sum = 41.0 + 78.3 = 119.3
Final answer will also have 1 decimal place = 119.3
1. 1.141
2. 119.3
HOPE THIS HELPS.
Answer:
13440 J
Explanation:
c ≈ 4200 J / (kg * °C)
m = 80 g = 0,08 kg
= 10 °C
= 50 °C
The formula is: Q = c * m * ()
Calculating:
Q = 4200 * 0,08 * (50 - 10) = 13440 (J)