Answer:
16.933g approximately 17.0 grams
Explanation:
From the simple promotions and given the same compound ascorbic acid (vitamin C)
In the laboratory synthesised ascorbic acid
Mass of carbon = 30.0g
Mas of Oxygen = 40.0g
That is the mass of Oxygen per unit mass of Carbon
Per gram of Carbon we have
(30.0g Carbon)÷30 combines with (40.0g of Oxygen)÷30
That is 4/3g of Oxygen per gram of Carbon
Hence the mass of Oxygen compound that combines with 12.7g of Carbonin natural occurring ascorbic acid (vitamin C) is = 4/3×12.7 = 16.933g approximately 17.0g
Answer : The final temperature of the copper is, 
Solution :
Formula used :

where,
Q = heat gained = 299 cal
m = mass of copper = 52 g
c = specific heat of copper =
= final temperature = ?
= initial temperature = 
Now put all the given values in the above formula, we get the final temperature of copper.


Therefore, the final temperature of the copper is, 
The answer would be the third one listed, Refraction
Answer:
VP (solution) = 171.56 mmHg
Explanation:
Vapor pressure of pure solvent(P°) - Vapor pressure of solution (P') = P° . Xm
Let's replace the data:
173.11 mmHg - P' = 173.11 mmHg . Xm
Let's determine the Xm (mole fraction for solute)
Mole fraction for solute = Moles of solute / Total moles
Total moles = Moles of solute + moles of solvent.
Let's determine the moles
Moles of solvent → 623.4 g / 119.4 g/mol = 5.22 moles
Moles of solute → 9.322 g / 180.1 g/mol = 0.052 moles
Total moles = 0.052 + 5.22 = 5.272 moles
Xm = 0.052 moles / 5.272 moles = 0.009 → 9/1000
173.11 mmHg - P' = 173.11 mmHg . 9/1000
P' = - (173.11 mmHg . 9/1000 - 173.11 mmHg)
P' = 171.56 mmHg
Answer is: 4) The same subscripts are on each side of the equation.
For example, balanced chemical reaction:
2Mg + O₂ → 2MgO.
1) The same number of atoms is on each side of the equation: two magnesium atoms and two oxgen atoms.
2) The formulas for all substances are correct: in magnesium oxide (MgO), magnesium has oxidation number +2 and oxygen -2, so formula is good, because compound must be neutral.
3) The same mass is represented on each side of the equation: because there is same number of atoms, the mass is the same.
4) The same subscripts are on each side of the equation: oxygen does not have same subscripts.