Q/Choose between parentheses 1- moles of substance contain ..... particles * (Non of these/18.066 ×10²³ /3.011 ×10²³ /6.022×10²³/12.044 × 10 ²³) 2-A compound’s molar mass is calculated by * (dividing the number of grams of the sample by Avogadro’s number/ adding the number of atoms present in the compound./ adding the atomic masses of all the atoms in the compound and expressing thatvalue in g/mol. / multiplying Avogadro’s number times the number of atoms present in thecompound./ Non of these)

Brasses are alloys in which copper is the primary component and zinc is the second most abundant element. Naval brass, which has a high resistance to salt corrosion is 60.0% Cu, 39.25% Zn, and 0.75% Sn. How many moles of zinc are present in a 72.1 gram sample of naval brass? Report your answer with three significant figures.

Select the quantity that contains the greater number of atoms in each of the following pairs of substance amounts. Make your selection using the periodic table, but without performing an actual calculation. a)  2.00 m o l e A r    OR   6.02 × 10 23 a t o m s N e                                [ Select ]                          ["2.00 moles of Ar", "6.02X10^23 atoms of Ar"]            b)  10.00 g o f F 2 OR    10.00 g o f O 2

MOLES/GRAMS/MOLECULES T06/S06 If a sample of HNO3 is found to contain 6.46 · 10-3 mol of H atoms how many moles of HNO3 molecules are present? Express your answer in scientific notation. Molar Mass (g/mol) HNO3 63.013 14.007 1.0080 15.999 N atom x 10 H atom O atom Avogadro's No. (mol*1) 6.022x1023

Use the References to access important values if needed for this question. According to the following reaction, how many moles of oxygen gas are necessary to form 0.625 moles carbon dioxide? carbon (graphite) (s) + oxygen (g) → carbon dioxide (g) Amount = mol

MOLAR VIEW T03/S01 How many moles of NHa+ ions are present in 2.30 · 10-3 mol of NH Br formula units? Express your answer in scientific notation. Molar Mass (g/mol) NH,Br 97.943 NH4+ ion 18.039 x 10 Br" ion 79.904 Avogadro's No. (mol*1) 6.022x1023

How many atoms of cobalt (Co) are in a sample of pure cobalt that is (4.18x10^-3) moles?

Converting between quantities To convert from a given quantity of one reactant or product to the quantity of another reactant or product • First, convert the given quantity to moles. Use molar masses to convert masses to moles, and use Avogadro's number (6.02 x 10 particles per mole) to convert number of particles to moles. • Next, convert moles of the given reactant or product to moles of the desired reactant or product using the coefficients of the balanced chemical equation. For example, in the chemical equation2H2 + O2-2H20the coefficients tell us that 2 mol of H2 reacts with 1 mol of Oz to produce 2 mol of H20. • Finally, convert moles of the desired reactant or product back to the desired units. Again, use molar masses to convert from moles to masses, and use Avogadro's number to convert from moles to number of particles. Reaction of hydrogen and nitrogen to form ammonia Hydrogen gas, H2, reacts with nitrogen gas, N2, to form ammonia gas, NH3, according to the equation 3H2(g) +…