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miv72 [106K]
3 years ago
15

I need help with the 2nd part first gets brainlist

Chemistry
1 answer:
mixer [17]3 years ago
8 0

Answer:

7. 4H₂O

Elements: Hydrogen, Oxygen

Number of molecules: 4

Number of elements: 8 H, 4 O

Number of Atoms: 12

Explanation:

The elements are determined by the their symbol i.e. H = hydrogen.

The number of molecules is determined by the coefficient ( the number in front of everything, in this case 4).

The number of elements is determined by the coefficient and the subscripts. Multiply the coefficient by the subscript after each element. When there is no subscript, it is equal to 1.  4H₂ = 4x2 = 8;  4O = 4x1 = 4.

The number of atoms is all the individual elements added together. 8+4 = 12.

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Solid solutions where one metal is dissolved in another is known as a(n) _____________.
krok68 [10]

Answer:

ionic solution

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The property of a substance stays ______________ no matter how the substance is used.
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3 0
3 years ago
The vapor pressure of ethanol is 30°C at 98.5 mmHg and the heat of vaporization is 39.3 kJ/mol. Determine the normal boiling poi
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Answer : The normal boiling point of ethanol will be, 348.67K or 75.67^oC

Explanation :

The Clausius- Clapeyron equation is :

\ln (\frac{P_2}{P_1})=\frac{\Delta H_{vap}}{R}\times (\frac{1}{T_1}-\frac{1}{T_2})

where,

P_1 = vapor pressure of ethanol at 30^oC = 98.5 mmHg

P_2 = vapor pressure of ethanol at normal boiling point = 1 atm = 760 mmHg

T_1 = temperature of ethanol = 30^oC=273+30=303K

T_2 = normal boiling point of ethanol = ?

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Now put all the given values in the above formula, we get:

\ln (\frac{760mmHg}{98.5mmHg})=\frac{39300J/mole}{8.314J/K.mole}\times (\frac{1}{303K}-\frac{1}{T_2})

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Hence, the normal boiling point of ethanol will be, 348.67K or 75.67^oC

3 0
3 years ago
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And water cannot be an element, because it is made of atoms of different types [H and Oxygen]
4 0
3 years ago
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