Question

12. What is the volume, in liters, of 12.0 moles of bromine? Bromine is a liquid at room temperature and has a density of 3.12 g/cm 13. Calculate the density of sulfur if you have 9.92x102 atoms in 2.51x10 L? UNITS 14. Calculate the number of hydrogen atoms in 0.252 ML of sulfuric acid. (D=1.02g/mL) 15. Indicate whether the following is true or false. If it is false, correct it to make it true. a. If you have 1 g samples of different elements, the sample with the smallest molar mass contains the fewest atoms. b. On average, one lithium atom weighs 6.941 amu. c. Every H atoms weighs 1.008 amu. d. A certain mass of solid Na (sodium) contains fewer atoms than the same mass of gaseous Ne (neon). e. One mole of NH3 weighs more than one mole of H20. f. The number of Cu atoms in 100 grams of Cu (s) is the same as the number of Cu atoms in 100 grams of copper (II)oxide. g. There are more hydrogen atoms in 2 moles of NH3 than in 2 moles of CH..!

all of them please!!!!!

Answer 1

12. moles of Be2 = 12 molar mass of Br = 160 Se, maos Bxy mola x molar mass mass Bly - 12 X160 = 1920 g Given, density = 3.12 g lema density = mass : volume= nolume : 1920 · 615:38 CM3 3.2 615.38 cm3 = 615.38 me & 615.38 8103 L volume = 0.615 L density ma volume density 13 Molar mass of S: 32 glonal So N atoms of s weigh 32 g 9.92 x 1023 atoms will 32 3 *9.92 X10 NA a mass of S = 32 x g. 92x10 23 6.02X1023 52739 density = mass & 52.13 - volume 2.51 X10 + x10-3 IML 10 6 L = 10 x 103 me = 10-3 me. So, density : 2.1 g/me 14. Ginen volume of the so = 0.252 me la density = 1.02 glme mass of h so = density & volume = 1:02 x 0.252 = 0.25704a NA

Now, molar mass of h SO = 98g ie 98 g of hso contains amole of H-alons 0.25704 9 of 150m will contain a x0.25704 = 5.24 X10-3 moles moles of H-alons : 5.24 x?o*3 males 15. (a) mas moles = mass moler mass mass is same moles & I molar mass Higher molar mass of element means it will have lower number of moles Higher are the moles, higher are the number of particles 'So The element having higher molar mass will I have less number of atoms So the statement is false (b) True statement (①) True statement-

id moles = mass - molar mass molar mass of Na = 23 g/mol mear mass of Ne=20g/me Since no. of So, So, Na has higher molar mass, it will have less moles than We for a given mass the less no of moles means less no of particles the statement is true (6) molar mass of N = lig - molar mass of 40 ² 18g The stalement is false. The tive statement is One mole of NH weight loss than one mole of Hol t Molar mass of Cu = 63.5 9 Imol So, 63.5 g of Cu contain MA aloms of Cu 100g u contains NA x 100 = 1.57N 63.5 Molar mass of CuO = 79.5 g/mol 79.5 g of Cuo contains N alons of cu 100 g of Cuo contains NA 1100 1.25 NA 19.5 The statement is false. The true statement is 100 g of Cucs) contains more number of u alons ! I than 100g of copper (I) oxide

Imole & mole Nh Nth contains contains 3 moles of 6 moles H- alones y H-alons Imole CH contains 4 moles of H-atoms. a mole H contains 8 moles of H-alons The statement is false. The truse statement is There are more M-alons in a moles of Cr than amoles of CHA in