Answer:
C. Moving Balloon 1 can make Balloon 2 move without the balloons touching.
Explanation:
When two balloons are rubbed with a wool cloth, they get electrostatic charge and both become negatively charged.
If both balloons will be place close together, balloon 1 will push the balloon 2 far from itself without touching it as they both are negatively charged and things with same charges repel each other.
Hence, the correct answer is "C. Moving Balloon 1 can make Balloon 2 move without the balloons touching."
Answer:
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
Explanation:
A buffer system is formed in 1 of 2 ways:
- A weak acid and its conjugate base.
- A weak base and its conjugate acid.
Determine whether mixing each pair of the following results in a buffer.
a. 100.0 mL of 0.10 M NH₃ with 100.0 mL of 0.15 M NH₄Cl.
YES. NH₃ is a weak base and NH₄⁺ (from NH₄Cl ) is its conjugate base.
b. 50.0 mL of 0.10 M HCl with 35.0 mL of 0.150 M NaOH.
NO. HCl is a strong acid and NaOH is a strong base.
c. 50.0 mL of 0.15 M HF with 20.0 mL of 0.15 M NaOH.
YES. HF is a weak acid and it reacts with NaOH to form NaF, which contains F⁻ (its conjugate base).
d. 175.0 mL of 0.10 M NH₃ with 150.0 mL of 0.12 M NaOH.
NO. Both are bases.
Wouldn’t it be pollution? Or......
Answer:
1.373 wt% Ca(OH)₂
Explanation:
Sample mix = 15.0g
Ca(OH)₂(aq) + 2HCl(aq) => CaCl₂(aq) + 2H₂O(l)
moles HCl = 0.2000g / 36 g·mol⁻¹ 0.0056 mol
moles Ca(OH)₂ = 1/2(moles HCl) = 1/2(0.0056 mol) = 0.0028 mol
mass Ca(OH)₂ = 0.0028 mol ( 74 g/mol ) = 0.206 g
mass % Ca(OH)₂ = (0.206/15.0)100% = 1.373 wt%
