1.) How many grams of B are there in a sample of B that contains
6.55×1023 atoms?
2.) A 19.35 gram sample of
chromium is heated in the presence of excess
fluorine. A metal fluoride is
formed with a mass of 33.49 g. Determine the
empirical formula of the metal fluoride.
(Enter the elements in the order Cr ,
F)
3.) A 25.34 gram sample of
chromium is heated in the presence of excess
iodine. A metal iodide is formed...
.Calculate the number of copper atoms in a 63.55 g sample of
copper. .What is the mass in grams of 0.509 moles of AlCl3? .Which
of the following 100.0 g samples contains the greatest number of
atoms?
a. Magnesium
b. Zinc
c. Silver
A mixture contains 0.250 Mol of Mn2O3 and 20.0 g of
MnO2.
1) How many atoms of oxygen are present in the mixture?
2) How many grams of manganese are in the mixture?
1. What is the approximate hemoglobin O2 saturation of a blood
sample that contains 10 g Hb/100 ml blood and has an O2 content of
10 ml O2/100 ml blood (ignore physically dissolved O2)? Show
work
2. About 40% of Ca2+ in the blood is bound to plasma proteins,
such as albumin. The [Ca2+] in Bowman’s Capsule is ~ 3 mEq/l,
whereas its concentration in the plasma is ~ 5 mEq/l. Why the
difference in [Ca2+] between these two compartments?...
A sample of CaCl2•2 H2O (calcium chloride dihydrate) contains
3.46x1021 atoms of chlorine. What is the mass of this sample in mg?
Enter your mass ROUNDED to 3 significant figures. Do not enter the
mg units. (written work)
A stainless steel alloy is to be analyzed for its chromium
content. A 3.00 g sample of the steel is used to produce 250.0 mL
of a solution containing Cr2O72−. A 10.0-mL portion of this
solution is added to BaCl2(aq). When the pH of the solution is
properly adjusted, 0.145 g BaCrO4(s)precipitates.
What is the percent Cr, by mass, in the steel sample?
A sample of a chromium-containing alloy weighing 3.450 g was
dissolved in acid, and all the chromium in the sample was oxidized
to 2CrO42–. It was then found that 3.18 g of Na2SO3 was required to
reduce the 2CrO42– to CrO2– in a basic solution, with the SO32–
being oxidized to SO42–. Write a balanced equation for the reaction
of 2CrO42– with SO32- in a basic solution. How many grams of
chromium were in the alloy sample? What was the...
1. A block of an alloy of mass 27.0 g and at a temperature of
277.22 K is placed in a calorimeter containing 41.0 g of water at
357.74 K. If the final temperature of the alloy and water is 303.59
K, calculate the specific heat (in J/g/K) of the metal. The
specific heat of water is 4.184 J/g/K. Express your answer to three
significant figures in scientific notation.
2.A 0.439 g sample of solid N(CH3)4Cl (s)
is dissolved in...