Reference no: EM132800215
-Determine the exact number of H atoms in the empirical formula of the compound composed of 59.960362% carbon, 13.417026% hydrogen and 26.623645% oxygen (by mass).
-Elemental analysis of an unknown compound shows it to contain 2.210175 g of hydrogen, 13.584983 g of phosphorus, and 21.051316 g of oxygen. How many hydrogen atoms are in the empirical formula of the compound?
-Granulated sugar (sucrose, C12H22O11) has an average density of about 0.82 g/cm3. Calculate the molarity of sucrose if 1.0 tsp of sugar is added to a 12 oz cup of coffee. 1.00 tsp = 4.93 cm3
-Acid rain is caused in part by burning coal that contains sulfur impurities. The sulfur is converted first to SO2, which reacts with oxygen and atmospheric moisture to produce sulfuric acid, H2SO4. If a particular coal contains 1.80% sulfur (by mass), calculate the mass of sulfuric acid produced by burning a metric ton (1000 kg) of the coal.
-Determine the formula mass of ammonium chloride (NH4Cl) from the following atomic masses. Be sure to express the answer to the appropriate number of significant figures. H - 1.00784 amu, N - 14.0067 amu, Cl - 35.453 amu
-The molar mass of any substance is numerically equivalent to its blank mass when expressed in amu.
-What is the mass of 2.38 mol of potassium carbonate (K2CO3)?
-The formulation and falsification of hypotheses are necessary components of any a) scientific law b) scientific theory c) scientific method d) scientific experiment e) scientific hypothesis
-How many protein molecules are contained in 1.56 ng of protein having a molar mass of 6.93 kDa?
-The empirical formula of a compound represents a) the relative masses of the constituent atoms. b) the total number of atoms in the molar mass. c) the relative number of atoms of each element. d) the percent composition of the compound by mass. e) the percent composition of the compound by volume.
-The molecular mass of a compound divided by the formula mass is equal to a)the number of grams per mole. b) the molecular weight of the compound. c)the total number of atoms in each molecule. d) the number of formula units per molecule. e) the number of molecules per mole.
-The molecular formula for a substance indicates a)the lowest whole number integer ratios of elements b)the number and type of each type of atom in the molecule c) which atoms are bonded to each other d)the average molar mass of each formula unit e) the number and type of isomeric forms
-An aqueous solution is one in which blank is the solvent.
-To calculate the number of molecules of a substance, the number of moles must be
a) divided by its formula mass.
b) multiplied by the molar mass.
c) divided by its density.
d) multiplied by Avogadro's number.
e) divided by the molar mass.