Answer:
Gold
Explanation:
Gold is cannot react with acids. Because gold is after hydrogen in the electrochemical row of metals.
Answer:
Work done, W = 128 kJ
Explanation:
Given that,
Weight of a mountain climber, F = 800 N
It climbs to a cliff that is 160 m high.
We need to find the work done by the mountain climber. The work done by an object is given by the formula as follows :
W = Fd
Put the values of F and d.
W = 800 N × 160 m
W = 128000 J
or
W = 128 kJ
So, 128 kJ of work is done by the mountain climber.
Required pH = 4.93
- OH⁻ from NaOH reacts with CH₃COOH giving CH₃COO⁻ and H₂O
- Let the volume of 3.5 M NaOH be x ml
Moles of NaOH = Moles of OH⁻ = Molarity * x ml = 3.5x mmol
- The reaction table for moles is as follows:
CH₃COOH + OH⁻ → CH₃COO⁻ + H₂O
Initial 60 3.5x 40
Change -3.5x -3.5x +3.5x
Final (60-3.5x) 0 (40+3.5x)
- Substitute in Henderson equation and solve for x:
pH = pKa + log
4.93 = 4.76 + log
0.17 = log
x = 5.62 ml NaOH required
Answer:
See explanation
Explanation:
According to Bohr's theory, when external energy is supplied to an atom, its electrons absorb energy and move from a lower energy level to a higher energy level.They quickly return to their original level and re-radiate the absorbed energy as a photo of light.
Hence, when an atom in ground state receives external energy, it becomes excited because energy is transferred to its electrons and they move from lower to higher energy level.