C.because the student started with sugar and water, and ended with sugar and water
Answer:
3.2 × 10³ J
Explanation:
Step 1: Given data
- Mass of the gold ring (m): 25 g
- Specific heat capacity of gold (Cp): 0.129 J/g.°C
- Initial temperature: 75 °C
- Final temperature: 1064 °C
Step 2: Calculate the temperature change (ΔT)
ΔT = 1064 °C - 75 °C = 989 °C
Step 3: Calculate the energy required (Q)
We will use the following expression.
Q = Cp × m × ΔT
Q = 0.129 J/g.°C × 25 g × 989 °C
Q = 3.2 × 10³ J
Answer:
[OH⁻] = 8x10⁻¹⁰
Explanation:
Kw = 1x10⁻¹⁴
Kw = [H₃O⁺] . [OH⁻]
1x10⁻¹⁴ = 1.25x10⁻⁵ . [OH⁻]
1x10⁻¹⁴ / 1.25x10⁻⁵ = [OH⁻]
[OH⁻] = 8x10⁻¹⁰
Put the mixture in water, the pebbles will sink, the pepper will float, and the sugar will dissolve