Answer:
[Ba^2+] = 0.160 M
Explanation:
First, let's calculate the moles of each reactant with the following expression:
n = M * V
moles of K2CO3 = 0.02 x 0.200 = 0.004 moles
moles of Ba(NO3)2 = 0.03 x 0.400 = 0.012 moles
Now, let's write the equation that it's taking place. If it's neccesary, we will balance that.
Ba(NO3)2 + K2CO3 --> BaCO3 + 2KNO3
As you can see, 0.04 moles of K2CO3 will react with only 0.004 moles of Ba(NO3) because is the limiting reactant. Therefore, you'll have a remanent of
0.012 - 0.004 = 0.008 moles of Ba(NO3)2
These moles are in total volume of 50 mL (30 + 20 = 50)
So finally, the concentration of Ba in solution will be:
[Ba] = 0.008 / 0.050 = 0.160 M
Answer:
2.56 grams of H₂S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH₃COO)₂
Explanation:
The balanced reaction is:
Pb(CH₃COO)₂ + H₂S → 2 CH₃COOH + PbS
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction) they react and produce:
- Pb(CH₃COO)₂: 1 mole
- H₂S: 1 mole
- CH₃COOH: 2 moles
- PbS: 1 mole
In this case, to know how many grams of H₂S are needed to produce 18.00 g of PbS, it is first necessary to know the molar mass of the compounds H₂S and PbS and then to know how much it reacts by stoichiometry. Being:
- H: 1 g/mole
- S: 32 g/mole
- Pb: 207 g/mole
The molar mass of the compounds are:
- H₂S: 2* 1 g/mole + 32 g/mole= 34 g/mole
- PbS: 207 g/mole + 32 g/mole= 239 g/mole
So, by stoichiometry they react and are produced:
- H₂S: 1 mole* 34 g/mole= 34 g
- PbS: 1 mole* 239 g/mole= 239 g
Then the following rule of three can be applied: if 239 grams of PbS are produced by stoichiometry from 34 grams of H₂S, 18 grams of PbS from how much mass of H₂S is produced?
mass of H₂S= 2.56 grams
<u><em>2.56 grams of H₂S is needed to produce 18.00g of PbS if the H2S is reacted with an excess (unlimited) supply of Pb(CH₃COO)₂</em></u>
Answer:
The correct answer is: <em>There must be potential energy in the bonds due to its particles position.</em>
Explanation:
Potential energy is a kind of energy which is stored in an object due to its position or configuration. For example, if there is a ball in the fifth floor of a building, it has a determined potential energy which is converted to kinetic energy when the ball fall down. The same is in the case of the chemical bonds: the particles or atoms have potential energy related to their relative positions in the system. In fact, chemical energy is considered a form of potential energy (stored in chemical bonds).
Answer:
5.00 × 10⁻⁴ mol HCl; 100 mL NaOH
Step-by-step explanation:
3. Moles of HCl
<em>Data:
</em>
V(HCl) = 500 mL
pH = 3
<em>Calculations:
</em>
pH = 3
[H₃O⁺] = 10⁻³ mol·L⁻¹
V = 500 mL × (1 L/1000 mL) = 0.500 L
Moles HCl = volume × concentration
= 0.500 L × (10⁻³ mol/1 L)
= 5.00 × 10⁻⁴ mol
4. Volume of NaOH
NaOH + HCl ⟶ NaCl + H₂O
<em>Data:
</em>
[NaOH] = 0.01 mol·L⁻¹
[HCl] = 0.02 mol·L⁻¹
V(HCl) = 50 mL
<em>Calculations:
</em>
Moles HCl = 0.050 L × (0.02 mol/1 L)
= 1.0 × 10⁻³ mol
Moles NaOH = 1.0 × 10⁻³ mol HCl × (1 mol NaOH/1 mol HCl)
= 1.0 × 10⁻³ mol NaOH
V(NaOH) = 1.0 × 10⁻³ mol NaOH × (1 L NaOH/0.01 mol NaOH)
= 0.1 L NaOH Convert to millilitres
= 100 mL NaOH
