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3 years ago

the grams of carbohydrate in one apple if the apple has no fat and no protein and provides 72 kcal of energy

1 answer:

5 0

<span>Carbohydrates have 4 kcal per gram of carbohydrates. (Protein is also 4 kcal/gram, while fat is 9 kcal/gram). Take the total kcal and divide by 4 kcal/gram: 72 kcal/(4 kcal/gram) = 18 grams carbohydrates.</span>

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Which of the following is not an example of a science? a.geology b.astrology c.astronomy d.ecology

Rasek [7]

I think it is b.astrology

6 0

3 years ago

. How many milliliters of 0.20 M HCl are needed to exactly neutralize 40. milliliters of 0.40 M KOH

Anuta_ua [19.1K]

Answer:

$V_{HCl}=80mL$

Explanation:

Hello,

In this case, for the given reactants we identify the following chemical reaction:

$KOH+HCl\rightarrow KCl+H_2O$

Thus, we evidence a 1:1 molar ratio between KOH and HCl, therefore, for the complete neutralization we have equal number of moles, that in terms of molarities and volumes become:

$n_{HCl}=n_{KOH}\\\\M_{HCl}V_{HCl}=M_{KOH}V_{KOH}$

Hence, we compute the volume of HCl as shown below:

$V_{HCl}=\frac{M_{KOH}V_{KOH}}{M_{HCl}} =\frac{0.40M*40mL}{0.20M} \\\\V_{HCl}=80mL$

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5 0

3 years ago

Identify the single displacement reaction. 2H 2 + O 2 ⟶ 2H 2O Al 2S 3 ⟶ 2Al + 3S Cl 2 + 2KBr ⟶ 2KCl + Br 2 C 4H 12 + 7O 2 ⟶ 6H 2

ozzi

Answer: $Cl_2+2KBr\rightarrow 2KCl+Br_2$

Explanation:

A single displacement reaction is one in which a more reactive element displaces a less reactive element from its salt solution. Thus one element should be different from another element.

$Cl_2+2KBr\rightarrow 2KCl+Br_2$

Synthesis reaction is defined as the reaction where substances combine in their elemental state to form a single compound. $2H_2+O_2\rightarrow 2H_2O$

Decomposition reaction is defined as the reaction where a single substance breaks down into two or more simpler substances.

$Al_2S_3\rightarrow 2Al+3S$

Combustion is a type of chemical reaction in which hydrocarbons burn in the presence of oxygen to form carbon dioxide and water along with heat.

$C_4H_{12}+7O_2\rightarrow 6H_2O+4CO_2$

6 0

3 years ago

A gas mixture contains 10.0 mole% H2O (v) and 90.0 mole % N2. The gas temperature and absolute pressure at the start of each of

Rainbow [258]

Answer: (a). T = 38.2 °C (b). V = 1.3392 cm³ (c). ii and iii

Explanation:

this is quite easy to solve, i will give a step by step analysis to solving this problem.

(a). from the question we have that;

the Mole fraction of Nitrogen, yи₂ = 0.1

Also the Mole fraction of Water, yн₂o = 0.1

We know that the vapor pressure is equal to the partial pressure because the vapor tends to condense at due point.

ρн₂o = ṗн₂o

= yн₂oP = 0.1 × 500 mmHg = 50 mmHg

from using Antoine equation, we apply the equation

logρн₂o = A - B/C+T

T = B/(A - logρн₂o) - C

= 1730.63 / (8.07131 - log 50mmHg) - 223.426

T = 38.2 °C

We have that the temperature for the first drop of liquid form is 38.2 °C

(b). We have to calculate the total moles of gas mixture in a 30 litre flask;

n = PV/RT

n = [500(mmHG) × 30L] / [62.36(mmHGL/mol K) × 323.15K] = 0.744 mol

Moles of H₂O(v) is 0.1(0.744) = 0.0744 mol

Moles of N₂ is 0.9(0.744) = 0.6696 mol

we have that the moles of water condensed is 0.0744 mol i.e the water vapor in the flask is condensed

Vн₂o = 0.0744 × 18 / 1 (g/cm³)

Vн₂o = 1.3392 cm³

Therefore, the volume of the liquid water is 1.3392 cm³

(3). (ii) and (iii)

The absolute pressure of the gas and The partial pressure of water in the gas would change if the barometric pressure drops.

cheers i hope this helps!!!!

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3 years ago

Which best represents the law of conservation of mass?

makkiz [27]

Mass of reactants &gt mass of products

6 0

3 years ago

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