Solar Radiation(Basically Radiation)
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,
Answer:
To convert a decimal into scientific notation, move the decimal point until you get to the left of the first non-zero integer. The number of places the decimal point moves is the power of the exponent, because each movement represents a "power of 10".
Answer:
It is the minimum amount of analyte that produces a signal which can be measured with reasonable accuracy - LOQ
The concentration is equal to three times the standard deviation of the signal from the blank divided by the slope of the calibration curve - LOD
The concentration is equal to 10 times the standard deviation of the signal from the blank divided by the slope of the calibration curve - LOQ
It is the minimum amount of analyte that produces a signal that is significantly different from the blank - LOD
Explanation:
We define the limit of detection has the lowest amount of analyte that produces a signal that is significantly different from a blank solution ( the absence of the substance). It is calculated as three times the standard deviation of the signal from the blank divided by the slope of the calibration curve.
The limit of quantitation (LOQ) is defined as the minimum amount of analyte that produces a signal which can be measured with reasonable accuracy. It is measured as 10 times the standard deviation of the signal from the blank divided by the slope of the calibration curve.
Hey there!
The pH of a weak base (in this case, pyridine is a weak base) is calculated by using the weak base equation, and then solving it.
C5H5N; Kb= 1.7 x 10⁻⁹
pH = -log [H⁺]
we can also say that pH = 14 + log [OH⁻]
Plugging into the weak base equation, we know that Kb = [OH⁻][BH⁺] / [B]
This can be solved using an ice chart, which will then simplify to :
Kb = [x][x] / [0.50-x]
We can assume that x is very small in comparison to the 0.5 , so we consider it zero.
Then plug in and solve for x. 1.79 *10-9 = x² / 0.5
x = 2.992 * 10⁻⁵
ince X is equal to the [OH⁻] concentration, we can plug it into the second pH equation, and get the pH!
pH = 14+ log 2.99 * 10⁻⁵
pH = 9.48
Hope that helps!
