Question

Qustion Campleon Status: QUESTION 7 What is the mass of a 4.110-mol sample of sodium hydroxide? Oa. 98.6 g Ob0.1028 g Oc 164,4 g O d.9.732 g Oe. 40.00 g QUESTION 8 A sample of ammonia has a mass of 89.9 g. How many molecules are in this sample? Oa541 x 1025 molecules Ob.5.28 molecules Oc3.18x 1024 molecules Od 1.14 x 1023 molecules x 10-15, molecules QUESTION 9 A mole of a chemical substance represents Oa.6.02 x 1025 chemical particles of the substance Ob. the mass of the substance that will combine with 100.0 g of oxygen grams of the substance d. the mass of the substance that will combine with 12.0 g of carbon 6.02 x 1025 Click Save and Submit to soue and submit. Clieck Save All Ansuers to save all anscers

Answer 1

* Mass of 4.110 mol NaOH sample. & molar mass of NaOH (soduim hydroxide) IM Na mo m = - 22.989 g/mol = 15.999 g/mol 1.0079 g/mol So molar mass = 1.0079 22.989 + 15.999 + = 39.996 g/mol ~ 40 g/mol Mass of = Noon No. of moles x = 4.110 mol X - molar mass 40 g/mol - 164.9 g Option ② is correct :- 16 Mais = of Ammonia Sample 89.9 9 mole miles=2 2 To calculate the moles, use the equation Number of moles Given mass. molar mass Scanned with CamScanner

Geven mass of ammonia = 89.99 molar mass of ammonia = 179/mol. Number of moles o - 89.9 g 17g/mol = 5.28 mol. Ace to 1 mole number Avogadro's haw of substance 6. 023 x 1023 contains avogadro's of particles. Thus 5.28 moles of ammonia contain = 6.023x10" X 5.28 = 31.83 x 1023 molewle. . 3.18 x 1024 molecules. Hence, option - © 2 t correct 3.18 x 1024 molecules Mole chemical substance esents! According to Avogadro's Law: I mole of substance contains avogadro's number 7 6.023 x 1023 chemical particles of substance. CamScanner

The the a mole number certain allows suentists of elementary mass of given en to calculate entities in substance Avogadros number is number: there are entities in I mole an 6.02 absolute x 1023 elementary . 1 mol contains 6.02 x 1023 the substance chemical of the su Hence option 6.02% 1023 substance. (a) is chemical correct particles of the as Scanne