A beaker with 125 mL of an acetic acid buffer with a pH of 5.000 is sitting on a benchtop. The total molarity of acid and conjugate base in this buffer is 0.100 M. A student adds 7.00 mL of a 0.360 M HCl solution to the beaker. How much will the pH change? The pKa of acetic acid is 4.740.
In: Chemistry
iron nail and copper (II) sulfate the compound contains Fe2+
molecular equation
ionic equation
net ionic equation
spectator ions
In: Chemistry
3Mg +2AlCl3 -------> 2Al +3MgCl2
a)calculate the mass of aluminium chloride that will react with 40g
of magnesium.
b) calculate the mass of each product formed from the reaction of 40g of mg
2)when propane gas C3H8 is burned with oxygen 50g of water is collected.what mass of propane was burned?
3)metallic iron can be produced by reacting iron(iii) oxide with carbon as shown below.when 100g of iron(iii)oxide is reacted, 45g of iron metal is obtained.what is the percent yield of the reaction?
In: Chemistry
current event or recent research related to atoms,atomic structure or chemical bonds.
In: Chemistry
1. A soil has the following cations reported as cmolc per kg of soil Ca = 6; Mg = 4; K = 3; Na = 2; Al3+ = 10.
a. Calculate the CEC of the soil (cmolc per kg) ( 1 point)
b. Calculate the base saturation (2 points)
c. How much CaCO3 needs to be added to this soil to raise the base saturation to 80%? (3 points)
d. How much CaO needs to be added to this soil to raise the base saturation to 80%? (4 points)
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A mixture of methane (CH4) and ethane (C2H6) is stored in a container at 294 mm Hg. The gases are burned in air to form CO2 and H2O. If the pressure of CO2 is 346 mm Hg measured at the same temperature and volume as the original mixture, calculate the mole fraction of the gases.
Mole fraction of methane: _____________
Mole fraction of ethane: _________________
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Write a balanced net ionic equation for the reaction of manganese(II) hydroxide, Mn(OH)2, with hydrochloric acid.
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Mn(OH)2(s) + 2H+(aq) ---> Mn2+(aq) + 2H2O(l) |
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Mn(OH)2(s) + 2H+(aq) ---> MnH2(s) + 2OH−(aq) |
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(OH)3(aq) + 3H+(aq) ---> 3H2O(l) |
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3OH−(aq) + 3H+(aq) ---> 3H2O(l) |
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Mn2+(aq) + 2Cl−(aq) ---> MnCl2(aq) |
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Question:1
You dissolve 312 mg of a compound
(AwBxCyDz) in water
producing 14.31 mL of solution and use the photometer and standard
solutions to find that the concentration of the A is 1.24 x
10-2 M. The molar mass of A is 114.52 g/mol.
Moles of A in the solution sample:________________________________
Mass of A in the solution sample: _________________________________
Mass % of A in the compound: _______________________________
Moles of A in 100 grams of the compound:
________________________________
Question:2
The compound, AwBxCy, like all
compounds has an oxidation number of 0 (zero). The oxidation number
of A is +1, the oxidation number of B is +2, and the oxidation
number of C is –1. If there are two moles of A for every 3 moles of
C in one mole of the compound, what is the empirical formula of the
compound?
Question:3
Given the compound,
KwAlx(SO4)y(H2O)z.
100.00 grams of the compound contains 8.24 grams of potassium and
5.69 grams of aluminum. What is the formula of the compound?
In: Chemistry
1. Retention time (tR) is a measure of how long a compound is retained on a stationaryphase in column in column chromatography. In TLC, Rf was a measure of how long thecompound was retained on the stationary phase. What is the relationship between tR and Rf?
2. What would be the order of elution if one separated the pigments of spinach on columnchromatography?
3. What if any would you have to change in terms of the mobile phase if you wanted toactually perform the column chromatography in order to separate the pigments of spinachcompare to the one used for the TLC Experiment? Explain.
4. Why is it important to keep the solvent level above the stationary phase? What wouldhappen if one lets the solvent get much lower than the alumina stationary phase?
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Discuss the relationship between a gas chromatogram and mass spectrometry data. How do they correspond to identify the compounds present?
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N, N'-Dimethylformamide (DMF) is a commonly-used polar solvent. Its normal boiling point is 426K and is has ΔH°vap = 47.6 kJ/mol. Suppose a laboratory vacuum system is able to maintain a flask at total pressure of 5.0 Torr. Estimate the temperature at which DMF will boil in this flask.
Please show all work.
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8C How many liters of a 3.14 M K2SO4 solution are needed to provide 81.3 g of K2SO4 (molar mass 174.01 g/mol)? Recall that M is equivalent to mol/L.
Expresss your answer to three significant figures.
7B Gastric acid pH can range from 1 to 4, and most of the acid is
HCl.
For a sample of stomach acid that is 1.26×10−2M in HCl, how many moles of HCl are in 12.1 mL of the stomach acid?
Express the amount to three significant figures and include the appropriate units.
PLEASE, IF YOU CAN, ANSWER ALL OF THEM I WOULD GREATLY APPRECIATE IT!
In: Chemistry
An aqueous solution of formic acid, HCOOH, is prepared at 0.075 M. The acid-ionization constant is Ka = 1.8 x 10-4. Because this is a weak acid, you may presume that the ionic strength is negligible (m = 0). Calculate:
a) the pKa of HCOOH
b) [H+]
c) [HCOO-]
d) [HCOOH] at equilibrium
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1.00 mol of A and 1.00 mol of B are placed in a 4.00-L container. After equilibrium is established, 0.400 mol of D is present in the container. Calculate the equilibrium constant for the reaction: A(g) + 3 B(g) <---> C(g) + 2 D(g)
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