Answer:
11.45kcal/g
2.612 × 10³ kcal
Explanation:
When a compound burns (combustion) it produces carbon dioxide and water. The combustion of 2-methylheptane can be represented by the following balanced equation:
2 C₈H₁₈ + 25 O₂ ⇄ 16 CO₂ + 18 H₂O
It releases 1.306 × 10³ kcal every 1 mol of C₈H₁₈ that is burned.
<em>What is the heat of combustion for 2-methylheptane in kcal/gram?</em>
We know that the molar mass of C₈H₁₈ is 114.0g/mol. Then, using proportions:

<em>How much heat will be given off if molar quantities of 2-methylheptane react according to the following equation? 2 C₈H₁₈ + 25 O₂ ⇄ 16 CO₂ + 18 H₂O</em>
In this equation we have 2 moles of C₈H₁₈. So,

The rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.
<h3>Rate of reaction</h3>
The rate of a chemical reaction is the rate at which the concentration of reactant molecules decreases or the concentration of product molecules increases.
<h3>Factors effecting rate of chemical reaction </h3>
The factors that affect the rate of chemical reaction include:
- Temperature: increase in temperature increases reaction rate while decrease in temperature decreases reaction rate.
- Catalysts: the present of catalysts increase the reaction rate. Some catalysts decreases reaction rate and are known as negative catalysts.
- Surface area: increase in surface area of reactants increases reaction rate.
- Concentration: Increase in concentration of reactants increases reaction rate while decrease in concentration of reactants decreases reaction rate.
Therefore, the rate of a chemical reaction is affected by temperature, Catalysts, Suface area, Concentration.
Learn more about rate of reaction and factors affecting reaction rate at: brainly.com/question/15841605
Explanation:
Sodium and potassium are in the same group on the periodic table because they both have similar number of valence electrons (1 electron) in their shells
Na = 2,8,1
K = 2,8,8,1
The molecular formula of dimethyl sulfoxide is
. Molar mass of dimethyl sulfoxide is 78.13 g/mol. Calculate number of moles as follows:

From the molecular formula, 1 mole of dimethyl sulfoxide contains 2 moles of Carbon, 6 moles of Hydrogen, 1 mole of Sulfur and 1 mole of oxygen.
Thus, 91.38 moles of dimethyl sulfoxide will have:
Carbon :

Hydrogen:

Sulfur:

Oxygen:

Since, 1 mole of an element equals to
atoms thus, number of atoms can be calculated as:
Carbon:

Thus,

Hydrogen:

Thus,

Sulfur:

Thus,

Oxygen:

Thus,

Therefore, number of C, S, H and O atoms are
respectively.