I need help with this too:(( did u get it?
Answer:
T₂ = 19.95°C
Explanation:
From the law of conservation of energy:

where,
mc = mass of copper = 37.2 g
Cc = specific heat of copper = 0.385 J/g.°C
mw = mass of water = 188 g
Cw = specific heat of water = 4.184 J/g.°C
ΔTc = Change in temperature of copper = 99.8°C - T₂
ΔTw = Change in temperature of water = T₂ - 18.5°C
T₂ = Final Temperature at Equilibrium = ?
Therefore,

<u>T₂ = 19.95°C</u>
Answer:
One can of cola contain 0.16 kcal of carbohydrates.
Explanation:
Given data:
mass of cola can = 40 g
kilocalories of carbohydrates = ?
Solution:
we know that there are 4 cal of carbohydrates per gram.
40 g × 4 cal/g = 160 cal
Now we will convert calories into kilocalories. There are 1000 calories in one kilocalories so,
160/1000 = 0.16 kcal
so, one can of cola contain 0.16 kcal of carbohydrates.
The answer is <span>b. 1% H, 42% Cl, 57% O.</span>
Let's first calculate a molar mass (M) of HClO₃. <span>Molar mass is a mass of 1 mole of a substance. It can be expressed as the sum of relative atomic masses (Ar), which are masses of atoms of the elements:
</span>M(HClO₃) = Ar(H) + Ar(Cl) + 3Ar(O)
Ar(H) = 1 u
Ar(Cl) = 35.5 u
Ar(O) = 16 u
M(HClO₃) = Ar(H) + Ar(Cl) + 3Ar(O) = 1 + 35.5 + 3 · <span>16 = 84.5 u
Now, we just need to calculate mass percent of each element using the proportion:
Ar : x = M : 100% </span>⇒ x = Ar ÷ M · 100%
Hydrogen: x = Ar(H) ÷ M · 100% = 1 ÷ 84.5 · 100% = 1.2% ≈ 1%
Chlorine: x = Ar(Cl) ÷ M · 100% = 35.5 ÷ 84.5 <span>· 100% = 42%
</span>Oxygen: x = 3Ar(O) ÷ M · 100% = 48 ÷ 84.5 · 100% = 56.8% ≈ 57%
The substance used for decolorization of undesirable color in a crystalline substance is powdered animal charcoal
Decolorization is the process of eliminating organic contaminants with vivid colors from the sample mixture.
Unwanted colors are removed by boiling the item with a suitable amount of powdered animal charcoal in a hot solution that has been filtered so that the charcoal may absorb the colors. The charcoal is a finely divided carbon.
Learn more about decolorization -
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