Chemistry: Unit 7 ReviewName:
True or False:
_____ 1. Hydrogen bonds are chemicals bond between hydrogen and oxygen in the same water molecule.
_____ 2. Two chlorine molecules (Cl2) are most likely attracted together by dispersion forces.
_____ 3. Surface Tension of any polar substance is caused by the large mass of the particles.
_____4. Water will have a higher vapor pressure than most nonpolar molecules with molar masses similar to that of water.
_____5. Water is most dense in the liquid phase, typically around 4 oC.
_____ 6. In an aqueous solution, water acts as the solute.
_____ 7. Surfactants increase surface tension by increasing the strength of the intermolecular attractions.
_____ 8. Calcium carbonate and Iron phosphate are soluble in water.
_____ 9. Ionic compounds with alkali metals/ammonium are usually water soluble.
_____ 10. Water and oil are miscible because they have different polarities.
_____ 11. Na2SO4•10H2O is the anhydrous form of sodium sulfate.
_____ 12. Solvent vapor pressures decrease as solute is dissolved because the solvent mass always increases
Free Response: Explain your answers.
13. Explain why water is a polar molecule
14. Which of the following bonds is not usually found in hydrogen bonds? Why?
a. N – Hb. O – Hc. C – Hd. Cl – H
15. Compared to methane (CH4), water has a (higher / lower ) vapor pressure. ______. Why?
16. The specific heat of liquid water is ______cal/g oC.
17.Surfactants (increase / decrease ) the surface tension of water. ______. Why?
18.Which of the following substances will be insoluble in water?
a. NaNO3b. MnCO3c. ZrCl4d. LiSO4
19.What kind of molecular interaction is found in hydrates? ______
20. If the anhydrous crystal of an ionic salt was more stable than the hydrated crystal, would the ionic salt be more willing to be efflorescent or hydroscopic? Why?
21. Sucrose (table sugar) is water-soluble but not an electrolyte, why?
22. Explain why suspensions produce the Tyndall effect but solutions don’t.
23. A 125 mL solution of 0.245 M silver nitrate is mixed with 47.5 mL of 0.510 M cupric chloride.
a. which of the solutions is the limiting reagent?
b. calculate the mass of silver chloride that is precipitated from this mixture.
Old stuff: Be sure to show work.
23. How many protons, neutrons and electrons are there in Se-75?
24. What is the chemical formula for Magnesium phosphate? For Tetraphosphorus decaoxide?
25. Write the balanced chemical equation for the single replacement reaction of iron metal and aqueous nickel nitrate that produces ferrous nitrate and nickel metal.
26. A 0.600L container of nitrous oxide (N2O) at 46.0 oC has a pressure of724 torr. How many grams of N2O are here?
27. Determine the empirical and molecular formulas of nicotine that contains 74.1% carbon, 8.6% hydrogen, 17.3% nitrogen and the molar mass is about 160 g/mol.