Answer: 27.09 ppm and 0.003 %.
First, <u>for air pollutants, ppm refers to parts of steam or gas per million parts of contaminated air, which can be expressed as cm³ / m³. </u>Therefore, we must find the volume of CO that represents 35 mg of this gas at a temperature of -30 ° C and a pressure of 0.92 atm.
Note: we consider 35 mg since this is the acceptable hourly average concentration of CO per cubic meter m³ of contaminated air established in the "National Ambient Air Quality Objectives". The volume of these 35 mg of gas will change according to the atmospheric conditions in which they are.
So, according to the <em>law of ideal gases,</em>
PV = nRT
where P, V, n and T are the pressure, volume, moles and temperature of the gas in question while R is the constant gas (0.082057 atm L / mol K)
The moles of CO will be,
n = 35 mg x 
x 
→ n = 0.00125 mol
We clear V from the equation and substitute P = 0.92 atm and
T = -30 ° C + 273.15 K = 243.15 K
V = 
→ V = 0.0271 L
As 1000 cm³ = 1 L then,
V = 0.0271 L x 
= 27.09 cm³
<u>Then the acceptable concentration </u><u>c</u><u> of CO in ppm is,</u>
c = 27 cm³ / m³ = 27 ppm
<u>To express this concentration in percent by volume </u>we must consider that 1 000 000 cm³ = 1 m³ to convert 27.09 cm³ in m³ and multiply the result by 100%:
c = 27.09 
x 
x 100%
c = 0.003 %
So, <u>the acceptable concentration of CO if the temperature is -30 °C and pressure is 0.92 atm in ppm and as a percent by volume is </u>27.09 ppm and 0.003 %.
Answer:
B. Poor conductor.
Explanation:
It cannot be A, as only 1 metal is not solid at room temp.
It cannot be C, as most metals are ductile.
It cannot be D, as most metals are malleable.
This leaves B, which is not true about metals, as a lot are very good conductors.
Let us differentiate accuracy from precision. Accuracy is the nearness of the measured value to the true or exact value. On the other hand, precision is the nearness of the measured values between each other. So, for precision, select the student in which the measured values are very near to each other. That would be Student III. Now, for accuracy, let's find the average for each student.
Student I: (<span>8.72g+8.74g+8.70g)/3 = 8.72 g
Student II: (</span><span>8.56g+8.77g+8.83g)/3 = 8.72 g
Student III: (</span><span>8.50g+8.48g+8.51g)/3 = 8.50 g
Student IV: (</span><span>8.41g+8.72g+8.55g)/3 = 8.56 g
From the given results, the accurate one would be Students I and II. So, we make a compromise. Even though Student III is precise, it is not accurate. If you compare between Students I and II, the more precise data would be Student I. Therefore, the answer is Student I.</span>
Answer:
0.1410 M
Explanation:
We'll begin by writing the balanced equation for the reaction. This is illustrated below:
HCl + NaOH —> NaCl + H₂O
From the balanced equation above,
The mole ratio of the acid, HCl (nA) = 1
The mole ratio of the base, NaOH (nB) = 1
Next, the data obtained from the question. This include:
Volume of acid, HCl (Va) = 25 mL
Volume of base, NaOH (Vb) = 34.55 mL
Concentration of base, NaOH (Cb) = 0.1020 M
Concentration of acid, HCl (Ca) =?
CaVa / CbVb = nA/nB
Ca × 25 / 0.1020 × 34.55 = 1/1
Ca × 25 / 3.5241 = 1/1
Cross multiply
Ca × 25 = 3.5241 × 1
Ca × 25 = 3.5241
Divide both side by 25
Ca = 3.5241 / 25
Ca = 0.1410 M
Therefore, the concentration of the acid, HCl is 0.1410 M
I use the acronym LEO for oxidation reactions. This stand for: Lose electrons Oxidation, so when oxidation occurs, electrons are lost. Due to electrons having a negative charge, substance undergoing oxidation have a more POSITIVE charge.
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