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If A=15° and c=37, find a.
why is it that when you try to boil an egg in an open pot, and leave awhile, upon returning you've noticed the water decreases? what about the movement of water molecules? what if you decided to put a lid on the pot, what will be the movement of the water molecules?
What is the weight percent (w/w) of NaOH in a solution prepared by dissolving 30.0g of NaOH in 120.0g of H2O?
Two boats 1200 feet apart measures an angle of elevation of 35 degree and 42 degree to the top of a lighthouse. how tall is the lighthouse?
While working in a metal processing facility, Letlen had accidentally mixed two metal vats together reating an alloy. One vat was labeled for cadmium, while the other was not. It can be assumed that hese are of pure metal composition. To identify this metal, Letlen took 1.000 g of the homogenous alloy ample composed of cadmium and the unknown metal, dissolved, and diluted it to exactly 100.0 mL in a volumetric flask. A 20.00-mL aliquot was taken and titrated this using 22.82 mL of 0.05000 M EDTA
MW: Cd (112.411 g/mol)
a. Calculate the moles of Cd and the moles of unknown metal in the 20.00-mL aliquot.
b. Calculate the moles of Cd and the moles of unknown metal in the sample.
c. Calculate the mass (in g) of Cd and the mass (in g) of unknown metal in the sample.
d. What is the MW (in g/mol) of the unknown metal?
e. What is the identity of the unknown metal that Letlen accidentally mixed?
Two analysts determined composition of a 2.500-g soda ash sample. They divided sample into two equal 1.250-g parts and analyzed it separately through double indicator titration.
One of them dissolved sample in water to prepare a 250.0 mL stock solution. A 50.00 mL aliquot was titrated using 0.10 M HCl. A volume of 40.08 mL was measured using phenolphthalein indicator and 13.58 mL with the methyl orange indicator.
Another also also dissolved sample in water to prepare a 250.0 mL stock solution. However, they spilled the primary standard, 100% pure Na2CO3, in the solution. They titrated a 50.00 mL aliquot using 0.10 M HCl same way first one did. For methyl orange indicator, they measured a volume of 30.07 mL
MW: NaOH (40.00 g/mol), Na2CO3 (105.99), NaHCO3 (84.01)
a. What is/are component/s of original soda ash sample?
b. What is/are %composition (in %w/w) of original soda ash sample?
c. How much Na2CO3 (in grams) did second spill in solution?
Hint: You do not need vph to solve this
How many moles are in 987.0 grams of Ra(OH)2
a. A solution of HCl is known to be 0.5622 N. When titrated against KOH, 45.22 ml of the acid neutralized 48.23 ml of the base. Calculate the N of the base.1. A solution of HCl is known to be 0.5622 N. When titrated against KOH, 45.22 ml of the acid neutralized 48.23 ml of the base. Calculate the N of the base.
b. What is the N of the solution of KOH if 45.18 ml are required to neutralize 0.3000 g of pure oxalic acid dehydrate (H2C2O4°2H2O)?
Hint: N x ml = g/MW/no. of H+ or OH- or +cation x 1000
where N x ml = no. of milliequivalent weight and g/MW/no. of H+ or OH- or +cation x 1000 = no. of milliequivalent weight
Show that the function f defined by f(x) =1//x^2 is uniformly continuous on [5 ,∞].
A 0.00453 L of sodium chloride solution was needed in a 560 mg sample that assayed
87.1% (w/w) Na2SO4. Calculate the molar concentration of sodium chloride in the
solution.
