Question

1.93 1026 atoms Question 19 (1 point) What is the mass of 12.04 1023 atoms of O? 0 8.0g O 16g 0 32 g O 17 g Onone of these Question 20 (1 point) What is the mass in grams of 557 copper atoms? 1.46 10-23 g of Cu 5.88 10-20 g of Cu 3.54 104 g of Cu 5.28 1024 g of Cu ID 2.13 1028 g of Cu

Answer 1

93 m 19. 12.04 X10X3 atoms of 0 we know 6.02 X 10 23 asoms makes I mole So, I asom 100 x 1023 mo 19.04 X1023 atomo = 12.04 x/029 moles - 6.02 x 1023 moles. aromic mass of oie. mass of a mole 04 0 = 169 so, mass of a moles of 0 = 2x1bg I Answer Option © 20. 557 ce-atom atomic mass iie. mass of 1 mole Cee -atom = 63.5469 ip mass ef 6.022 X1023 cer-arom = 63.5469 So, mass of 1 ce-wom = 63.546 g m 6.022 X10239 So, mass of 557 Lu- utom = 63.546 *5579 6.022x1023 : 5.874 x1620g | Answer -Option ® 21. 2.7 g of B atomic mass lip mass of 1 mole B = 10.81g ie 10.819 of B = 1 mole 50 га в = MAe 2.79 of B = 27 mole 10.81

2.790 = 2.7 mole 10.81 = 0.8497 mole we know Imole has 6.022 X 10 122 X1023 atoms So, 0-8497 mulle han – 0.22497 x 6.022 X10's atomy 21.504 XI023 | Answer-Option ①]