Answer:
C) 170 Cal
Explanation:
We are given the composition of a food sample as;
Carbohydrate = 25 g
fat = 8 g
Protein = 5 g
We are needed to determine the energy content of the food;
We need to know the amount energy yielded by each food substance.
That is; carbohydrates and proteins generate 4 calories per gram while fats generates 9 calories per gram.
Therefore;
Amount of energy will be;
= (25 × 4 cal/g) + (8g × 9 cal/g) + (5 g × 4 cal/g)
= 172 cal
Approximately , 170 calories
Therefore, the energy content will be 170 calories
D) The movement of electrons between atoms
Answer:
The correct option is;
True
Explanation:
Combustion is a chemical reaction between components of a combustion reaction which are;
1) A fuel
2) An oxidizing agent
The oxidizing agent or oxidant in a combustion reaction consist mainly of oxygen.
A combustion reaction is an oxidation and reduction (redox) heat evolving (exothermic) reaction that takes place at high temperatures and produces smoke which consists of gaseous mixture of chemicals and sometimes very small solid particles
An exothermic reaction can be classed either as rapid, spontaneous, or explosive
A spontaneous exothermic reaction is one that begins on its own in atmospheric conditions and room temperature as the heat required to begin the reaction is produced by the initial oxidation of the reacting fuel
Example of a substance that undergoes spontaneous oxidation reaction is white phosphorus.
Answer:
(A) 28
Explanation:
To solve this problem we use the <em>PV=nRT equation</em>, where:
- P = 800 mmHg ⇒ 800/760 = 1.05 atm
- R = 0.082 atm·L·mol⁻¹·K⁻¹
- T = 25.0 °C ⇒ 25.0 + 273.16 = 298.16 K
We<u> input the data</u>:
- 1.05 atm * 2.00 L = n * 0.082 atm·L·mol⁻¹·K⁻¹ * 298.16 K
And <u>solve for n</u>:
Now we calculate the gas' mass:
- Gas Mass = (Mass of Container w/ Gas) - (Mass of Empty Container)
- Gas Mass = 1052.4 g - 1050.0 g = 2.4 g
Finally we <u>calculate the unknown gas' molar mas</u>s, using<em> its mass and its number of moles</em>:
- Molar Mass = mass / moles
- Molar Mass = 2.4 g / 0.086 mol = 27.9 g/mol
So the answer is option (A).
A compound is 2 or more substances chemically combined, mixtures arent
