Answer Happy

3. How many hydrogen atoms are in 2.50 g of pharmacolite, CaHAs04-2H:0 (MMass = 216.0 g/mol)? a. 6.97 x 1021 atoms of H b. 2.09 x 1022 atoms of H c. 2.79 1022 atoms of H d. 3.48 x 1022 atoms of H e. 4.18 x 1022 atoms of H 4. Paying attention to units can avoid disasters such as the Mars orbiter destruction in 1999. Two teams of scientists across the Atlantic worked in two different sets of units, metric and English resulting in a sad time in the quest for Mars exploration. To start, to escape Earth's orbit a space vehicle must reach a velocity beyond 25,000 mihr or it will remain orbiting the Earth. What would the escape velocity be in km/sec? 1km = 0.62137 mi. a. 11.176 km/sec b. 12.345 km/sec c. 670.6 km/sec d. 4.315 km/sec 5. To reach the escape velocity and beyond the rover needs a solid propellant. To my surprise the solid propellant most commonly used is ammonium perchlorate, NH CIOin a binding material. 2,020 kg of solid propellant is used in one rocket that burns for 90 seconds. Have you wondered how many oxygen atoms are present in that sample? Molar mass NH.CIO= 117.49 g/mol a 1.035 x 103 atoms 0 b. 4866 x 10% atoms c. 4.141 x 10 atoms o d. 1.035 x 1025 atoms 0 0.4.141 x 10atoms o 6. Aluminum is frequently used to build electronics due to its low cost and low weight. The molar mass of aluminum according to the periodic table is 26.97 g/mol; a small car has a mass of 1200, Kg. How many moles of aluminum have a mass equal to the mass of a small car? a. 3. 236 x 10' moles Al b. 1.85.4 x 10 moles Al c. 4.449 x 10 moles A! d. 44.49 moles Al