08 Oct How many anions are there in 4.50g of MgBr2?

How many anions are there in 4.50g of MgBr2?

 

 

 

2. What is the mass of 0.500 mol of dichlorodifluoromethane, CCl2F2?

 

 

 

3. Choose the heterogeneous mixture from the list below.

 

A). fluorine gas

 

B). chicken noodle soup

 

C). energy drink

 

D). carbon (diamond)

 

E) cola

 

 

 

4. Which of the following are examples of physical change?

 

A). Sugar is dissolve in water

 

B). Acetone evaporates

 

C). Ethanol evaporates

 

D). Dry ice sublimes

 

E). All of these are examples of physical change.

 

 

 

5. Identify the element that “X” represents. 14X6

 

 

 

6. Choose the homogeneous mixture from the list below.

 

A). walnut cookies

 

B). Tea

 

C). granola bar

 

D). chunky spaghetti sauce

 

E).  carbonate soda

 

 

 

7. Which of the following volumes is equal to 97 mL?

 

 

 

8. Identify the charges of the protons, neutrons, and electrons.

 

 

 

 

 

9. Determine the volume of hexane that contains 5.33 × 1022 molecules of hexane. The density of hexane is 0.6548 g/mL and its molar mass is 86.17 g/mol.

 

 

 

10. According to the following balanced reaction, how many moles of HNO3 are formed from 3.75 moles of NO2 if there is plenty of water present?

 

 

 

11. How many zinc atoms are contained in 3.75 moles of zinc?

 

 

 

12. How many moles of BCl3   are needed to produce 5.00g of HCl(aq) in the following reaction?

 

 

 

 

 

13. Which of the following is an example of intensive properties?

 

A). length

 

B). Gas

 

C). volume

 

D). None of the above is an example of intensive properties.

 

E). All of the above are examples of intensive properties.

 

 

 

14. Round off 801106 to four significant figures.

 

 

 

16. Aluminum metal reacts with aqueous iron (III) oxide to form aqueous aluminum oxide and iron metal. What is the stoichiometric coefficient for aluminum when the chemical equation is balanced using the lowest, whole-number stoichiometric coefficients?

 

 

 

17. Which of the following is an ionic compound?

 

 

 

18. Write a balancedequation to show the reaction of aqueous aluminum acetate with aqueous ammonium phosphate to form solid aluminum phosphate and aqueous ammonium acetate.

 

 

 

19. Identify a liquid at room temperature.

 

A). oil

 

B). copper

 

C). nitrogen

 

D). zinc

 

 

 

20. What mass (in kg) does 4.41 moles of copper have?

 

 

 

21. Balance the chemical equation given below, and determine the number of grams of MgO that are needed to produce 20.0 g of Fe2O3.

 

 

 

_____ MgO(s) + _____ Fe(s) → _____ Fe2O3(s) + _____ Mg(s)

 

 

 

 

 

22. Give the stoichiometric coefficient for oxygen when the following equation is balanced using the lowest, whole-number coefficients.

 

_____ C6H14O (l) + _____ O2 (g) → _____ CO2(g) + _____ H2O(l)

 

23. How many Zn atoms are contained in 922g of Zn?

 

 

 

24. How many Fe2+ ions are there in 25.0g of FeSO4

 

 

 

25. What is the mass of 6.44 × 1024 molecules of ClO2? The molar mass of ClO2 is 67.45 g/mol.

 

 

 

26. Calculate the mass (in kg) of 4.87 × 1025 atoms of Zn.

 

27. Identify the element whose ion only exists as 2+.

 

 

 

28. Choose the pure substance from the list below.

 

A). air

 

B). sea water

 

C). milk

 

D). salt

 

E). beer

 

 

 

29. Calculate the mass (in ng) of 2.33 × 1020 atoms of O.

 

 

 

30. Give the common use for sodium hypochlorite.

 

 

 

31. Which of the following is an example of physical change?

 

A). cooking vegetables

 

B). an oxygen balloon explodes when contacted with a flame.

 

C). ice melts

 

D). a Halloween light stick glows after shaking. 

 

E). None of the above is a physical change.

 

 

 

 

 

32. How many phosphorus atoms are contained in 158 kg of phosphorus?

 

 

 

33. How many moles are there in 3.50g of ethanol, CH3CH2OH?

 

 

 

34. Calculate the mass percent composition of oxygen in Al2(SO4)3.

 

 

 

35. What mass (in mg) does 2.63 moles of nickel have?

 

 

 

36. How many protons are in each neutral atom of arsenic?

 

 

 

37. Calculate the atomic mass of element “X”, if it has 2 naturally occurring isotopes with the following masses and natural abundances:

 

X-45 44.8776 amu 32.88%

 

X-47 46.9443 amu 67.12%

 

 

 

 

 

 

 

38. How many grams of water react to form 3.20 moles of Ba(OH)2?

 

BaO(s) + H2O(l) → Ba(OH)2(s)

 

 

 

39. Choose the compound from the list below.

 

A). neon  

 

B). water  

 

C). lithium

 

D). tin

 

E). sodium

 

 

 

40. Which of the following is equal to exactly Avogadro’s number of atoms?

 

 

 

41. Determine the molecular formula of a compound that has a molar mass of 92.0 g/mol and an empirical formula of NO2.

 

 

 

42. How many moles are in 2.16×1024   atoms of copper?

 

 

 

43. What is the empirical formula of a compound that is 40.9% C, 4.6% H, and 54.5% O by mass?

 

 

 

44. How many protons (p) and neutrons (n) are in an atom of strontium-90?

 

 

 

45. How many moles of C3H8 contain 9.25 × 1024 molecules of C3H8?

 

 

 

46. Identify a unit that is used for volume.

 

 

 

47. What mass (in g) does 3.99 moles of Kr have?

 

 

 

48. Which of the following is an example of a chemical change?

 

A). a match burns

 

B). ethanol evaporates

 

C). water condenses

 

D). liquid nitrogen evaporating

 

E). All of the above are examples of chemical change

 

 

 

49. Which of the following exists as a polyatomic molecule?

 

 

 

50. Choose the homogeneous mixture from the list below.

 

A). ice water

 

B). salsa

 

C). dirt

 

D). wine

 

E). mud