C. Distance from Earth
The observed brightness of a star (the apparent magnitude) to an absolute magnitude, you need to know the distance [d], to the star. Alternatively, if we know the distance and the apparent magnitude [m] of a star, we can calculate its absolute magnitude [d].
*paraphrased from "COSMOS.com"
Answer:
0.0184
Explanation:
Let's consider the following reaction at equilibrium.
2 HI(g) ⇌ H₂(g) + I₂(g)
The concentration equilibrium constant (Kc) is equal to the product of the concentration of the products raised to their stoichiometric coefficients divided by the product of the concentration of the reactants raised to their stoichiometric coefficients.
Kc = [H₂] × [I₂] / [HI]²
Kc = (4.78 × 10⁻⁴) × (4.78 × 10⁻⁴) / (3.52 × 10⁻³)²
Kc = 0.0184
Answer:
3.07 Cal/g
Explanation:
Step 1: Calculate the heat absorbed by the calorimeter
We will use the following expression.
Q = C × ΔT
where,
- C: heat capacity of the calorimeter (37.60 kJ/K = 37.60 kJ/°C)
- ΔT: temperature change (2.29 °C)
Q = 37.60 kJ/°C × 2.29 °C = 86.1 kJ
According to the law of conservation of energy, the heat released by the candy has the same magnitude as the heat absorbed by the calorimeter.
Step 2: Convert 86.1 kJ to Cal
We will use the conversion factor 1 Cal = 4.186 kJ.
86.1 kJ × 1 Cal/4.186 kJ = 20.6 Cal
Step 3: Calculate the number of Cal per gram of candy
20.6 Cal/6.70 g = 3.07 Cal/g
Answer:
Here's what I get
Explanation:
1. Sugar
(a) Dissolving in water
The white solid dissolves in water to give a colourless solution. There is no evidence that a new substance is being produced.
(b) Addition of sodium hydroxide
Adding the colourless solution of sodium hydroxide to the colourless sugar solution gives a colourless solution. There is no evidence that a new substance is being produced.
2. Magnesium sulfate
(a) Dissolving in water
The colourless crystals dissolve in water to give a colourless solution. There is no evidence that a new substance is being produced.
(b) Addition of sodium hydroxide
Adding the colourless solution of sodium hydroxide to the colourless solution of magnesium sulfate gives a white precipitate (see image). This is evidence that a new substance is being produced.
Answer:
B
Explanation:
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