Which of the following is generally true regarding the impact of the reduced speed limit?
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(a) It always reduces the atmospheric emissions from vehicles |
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(b) Whether it reduces the emission depends on the types of fuels (e.g., gasoline vs. diesel) |
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(c) Whether it reduces the emission depends on the types of pollutants (e.g., CO, HCs, NOx, PM) |
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(d) both (b) and (c) |
In: Chemistry
Calculate the molar mass of each Compound :
Gycerol
NaCl
CaCl
This is for the lab experiment on Molar Mass and freezing point,
and these are the results l got.
Solution. Freezing point in degreesC
H2O. 0
Gycerol. -3.5
NaCl. -5.7
CaCl. -4.0
How do these molar masses compare to the theoretical. Calculate the
percent error. glycerol I have 0.04470, and 0.0383 for NaCl and
0.01792 for CaCl. I know there is a constant l am supposed to use
to get the theoretical molar mass, but l am stuck. CALCULATE THE
PERCENT ERROR.
In: Chemistry
In: Chemistry
A [a]ml aliquot of a nitric acid of unknown concentration is pipetted into 125-ml Erlenmeyer flask and 2 drops of phenolphthalein are added. The [b] ml of sodium hydroxide with concentration [c]mol/l is used to titrate the nitric acid solution. What is the molar concentration (mol/l) of the nitric acid solution?
For [a], [b], and [c] each student would have a different set of data. Practice how to solve this problem if [a] =20.00ml of nitric acid, [b] =17.60ml of NaOH, and [c] =0.1092M NaOH.
A [a] mL volume of an H2A acid solution of unknown concentration
with 2 drops of phenolphthalein required [b] mL of [c] M NaOH to
reach the endpoint. What is the molar concentration of the acid
solution?
[a]= 22.51ml
[b]=24.62ml [c]=0.1201 M NaOH
A 0.200-g sample of impure NaOH required 18.25ml of 0.2406 M HCl for neutralization. What is the percent of NaOH in the sample? Show your work.
In: Chemistry
A mixture of propionic and n-butyric acids, which can be assumes to form ideal solutions, is to be separated by distillation a distillate containing 95 mol% propionic acid and a bottoms of 98 mol% n-butyric acid. Determine the type of condenser and estimate the distillation operating pressure. The normal boiling point for propionic acid is 141 C and n-butyric is 163.5 C.
In: Chemistry
a 5.00 g sample of TNT (C7H5N2O6) is burned in a bomb calorimeter with a heat capacity of 420 J/degreeC. The calorimeter contained 610 grams od water (4.18J/gdegreeC) and the temperature of the water was measured to go from 20.0 degree C to 22.5 degree C. What is the heat of combustion of TNT?.
I know the answer, but can you give me a step by step explanation of how to get it?
In: Chemistry
The fluorocarbon compound C2Cl3F3 has a normal boiling point of 47.6 ?C. The specific heats of C2Cl3F3(l) and C2Cl3F3(g) are 0.91 J/g?K and 0.67 J/g?K, respectively. The heat of vaporization for the compound is 27.49 kJ/mol.
Calculate the heat required to convert 46.0g of C2Cl3F3 from a liquid at 11.10?C to a gas at 81.20?C.
In: Chemistry
In the qualitative analysis scheme, magnesium and nickel precipitate from solution upon the addition of sodium hydroxide. Once separated from the remaining cations by filtration or decanting, the solid mixture is acidified and warmed to dissolve magnesium and nickel cations back into solution. Adding ammonia creates a buffer solution. (Remember, HCl and NH3 makes for NH4+ cation.) The buffered solution should just be basic (say, pH = 8). Adding sodium hydrogen phosphate (Na2HPO4) precipitates magnesium as MgNH4PO4 (Ksp = 3 x 10-13).
a. Write the Ksp expression for the dissociation of MgNH4PO4.
b. Calculate the molar solubility of the compound in pure water.
c.Calculate the [NH4+] in a pH of 8.
d. Calculate the molar solubility of MgNH4PO4 in a solution with pH of 8.
In: Chemistry
Draw sodium methoxide and potassium tert-butoxide. How are they different? What products do you expect from reacting each base with 2-bromoheptane? With 1-bromoheptane?
Explain what makes potassium tert-butoxide more sterically hindered than sodium methoxide and why sodium methoxide could also exhibit steric hindrance when it acts as a base.
What are possible side reactions for each of the reactions?
Why do you want to keep everything dry for this reaction?
In: Chemistry
When the temperature becomes sufficiently high, water vapor starts to decompose into hydrogen gas and oxygen gas according to 2H2O(g) A 2H2(g) + O2(g) Using the following data, and assuming that 6CP is constant for this reaction and has an effective value of Cp = 18.88 J mol–1 K–1 over the temperature range in question,
calculate: (a) the value of the decomposition constant at 1000 K
(b) the percent decomposition of water vapor at 1000 K and one bar total pressure.
H2(g) O2(g) H2O(g)
hf (298.15) (kJ mol–1) 0.00 0.00 –241.82
S298.15 o (J K–1 mol–1) 130.684 205.138 188.825
In: Chemistry
Find the pH of each of the following mixtures of acids.
7.0×10−2 molL−1 in HNO3HNO3 and 0.185 molL−1 in HC7H5O2
1.5×10−2 molL−1 in HBrHBr and 2.0×10−2 molL−1 in HClO4
9.0×10−2 molL−1 in HFHF and 0.230 molL−1 in C6H5OH
0.105 molL−1 in formic acid and 4.5×10−2 molL−1 in hypochlorous acid
In: Chemistry
1- A 30.00 mL wine sample is titrated with a 1.10×10-1M solution of sodium hydroxide. The equivalence point is determined to be 34.705 mL. What is the acidity of the wine expressed as (g tartaric acid / L; MW tartaric acid = 150.085 g/mole)?
2- The acidity of a wine sample is 1.15×101, expressed as (g citric acid / L wine; MW citric acid = 192.124 g/mole) . The sample is titrated with a 0.100 M solution of sodium hydroxide. The equivalence point is determined to be 23.391 mL. What is the volume of the wine sample analyzed in mL?
In: Chemistry
What is the theoretical yield in a reaction using 0.50g of N-tert-butoxycarbonyl-L-alanine, 0.63g methyl-L-phenylalaninate hydrochlroide, 0.4mL isobutyl chloroformate, and 0.3mL N-methylmorpholine to yield methyl N-tert-butoxycarbonyl-alanyl-phenylalaninate (Boc-Ala-Phe-OMe)?
In: Chemistry
The Kf for the formation of
Co(NH3)62+ is 7.70 ×
104.
The Kf for the formation of
Co(en)32+ is 8.70 × 1013.
Suppose a 500.0 mL solution contains 1.300 millimoles of
Co(NO3)2, 100.0 millimoles of NH3,
and 100.0 millimoles of ethylenediamine. What is the concentration
of Co2+(aq ) in the solution?
In: Chemistry
(1) Deduce the expressions relating pE to pH, the concentration of sulfate ion, and the partial pressure of hydrogen sulfide gas, given that for the half-reaction, pE° = —3.50 V when the pH is 7.0.
(2) Deduce the partial pressure of hydrogen sulfide when the sulfate ion concentration is 1Q^5 M and the pH is 6.0 for water that is in equilibrium with atmospheric oxygen.
In: Chemistry