Physical Science 20 - Final Exam Practice

Transcription

1 Physical Science 20 - Final Exam Practice SHORT ANSWER IS ALL CURVED MIRRORS AND LENSES Mirrors and Lenses 1. Complete the following ray diagrams for curved mirrors. Write the 4 characteristics of each image beside the diagram. (1. Location of image, 2. Upright or inverted, 3. Size, 4. Real or virtual)

2 2. For the following concave mirror, a. Locate and draw the image if the object is 3.5 cm from the vertex and has a height of 1.0cm. b. State the 3 characteristics of the image. Upright or inverted? Real or virtual? Size? c. Measure the hi:, di: and f: and state it belo 3. An object is 20cm from a concave mirror of 8cm focal length (16cm radius). What is the distance of the image? 4. An object 3cm high is placed 25cm from a concave mirror of 15cm focal length. Find the location and height of the image. 5. If the image of a person in a convex mirror is 25cm tall, appearing exactly one fourth the actual size, what is the height of the person? 6. An object 25 cm tall is standing cm from a convex mirror. a. What is the size of the image produced if the location of the image is -15cm (behind the mirror)? b. What is the focal length of the mirror? c. Is the image upright or inverted? Explain how you know. 7. Complete the following ray diagrams to locate the image of the object. State the characteristics of the image. (Note: you can draw and arrow through the middle of Garfield s body and locate that image.) a. b.

3 c. d. 8. What focal length of a concave lens is needed to form a virtual image that is -20.0cm from the len 9. convex lens is needed to produce an image located cm (in front of the lens) that is 2.5 time 10. A convex lens has a focal length of 9.0cm. A 1.5cm high object is placed 6.0 cm from the lens. a. What is the distance of the image? b. How large is the image? Chemistry Nomenclature and Types of Reactions Multiple Choice 1. What is the difference in electron interaction between ionic and covalent compounds? 2. What does the formula for an acid always contain? What does the formula for a base always contain? acid contains H + base contains OH - 3. If an acid names in ide, how is it named? As a hydro ic acid If an acid ends in ate, how is it named? As an ic acid If an acid ends in ite, how is it named? As an ous acid 4. Match the following: A) Acid C CO 2 B) Base D BaO C) Acidic oxide A H 2 CO 3 D) Basic oxide E AlBr 3 E) Salt B Ca(OH) 2

4 5. Using the activity series on your reference sheet, indicate which of the following single replacement reactions WILL or WILL NOT take place. a) 2Fe + Al 2 (SO 4 ) 3 2Al + Fe 2 (SO 4 ) 3 WILL or WILL NOT b) Mg + Zn(NO 3 ) 2 Mg(NO 3 ) 2 + Zn WILL or WILL NOT c) Sn + 2HCl SnCl 2 + H 2 WILL or WILL NOT 6. Balance the following reactions and name what type of reaction is occurring: a) NaCl + Ag 2 SO 4 AgCl + Na 2 SO 4 b) H 2 S + Al Al 2 S 3 + H 2 c) Al 2 O 3 Al + O 2 d) C 3 H 8 + O 2 CO 2 + H 2 O e) Li 2 O + H 2 O LiOH 7. For each of the following double replacement reactions, indicate the physical state of each of the products formed. Next, indicate if the reaction WILL or WILL NOT occur. a) CaC l2(aq) + K2 C O3(aq) CaC O3 (?) + 2KCl (?) WILL or b) Ba(OH) 2(aq) + 2HBr (aq) BaBr 2 (?) + 2H 2 O (?) WILL or c) 3NH 4 Cl (aq) + Na 3 PO 4(aq) (NH 4 ) 3 PO 4 (?) + 3NaCl (?) WILL or 8. List 4 things that can happen to indicate to you that a chemical change has taken place. 8. Which of the following double replacement reactions will occur. a) Pb(NO 3 ) 2(aq) + KI (aq) p WILL or WILL NOT b) (NH 4 ) 2 SO 4(aq) + Ba(OH) 2(aq) WILL or WILL NOT c) AgNO 3(aq) + Na 2 S (aq) WILL or WILL NOT d) MgCl 2(aq) + NaOH (aq) WILL or WILL NOT Mole Concept and Stoichiometry 1. Using your Molarity formula, calculate the missing value from the following: a) 10.0 moles, 2.00 M b) 50.0 moles, 2.00 L c) 500 ml, 0.5 mol/l = 5.00 L = 25.0 M = 0.3 moles 2. Find the molar mass of CH 3 COOH. Find the molar mass of BaF 2

5 L x 1000 ml = 4250 ml 1L 4. The chemical equation below describes what happens when a match is struck against a rough surface to produce light and heat. P 4 S 3 (s) + 8 O 2 (g) P 4 O 10 (g) + 3 SO 2 (g) a) Balance this chemical equation b) If 5.3 L of oxygen gas at STP were consumed, what volume of sulfur dioxide at STP would be produced? c) What mass of P 4 S 3 would be consumed in the same reaction described in (b)? d) If you had 0.8 mol of P 4 S 3, how many particles of P 4 O 10 would be produced? a) 5.3 L O 2 x 1 mol O 2 x 3 mol SO 2 x 22.4 L SO 2 = L SO 2 = 2.0 L SO L O 2 8 mol O 2 1 mol SO 2 b) 5.3 L O 2 x 1 mol O 2 x 1 mol P 4 S 3 x g P 4 S 3 = g P 4 S 8 = 6.5 g P 4 S L O 2 8 mol O 2 1 mol P 4 S 3 c) 0.8 mol P 4 S 3 x 1 mol P 4 O 10 x 6.02 x particles P 4 O 10 = x particles P 4 O 10 1 mol P 4 S 3 1 mol P 4 O 10 = 5 x particles P 4 O Use the ham sandwich reaction given for the following 3 questions: 4 B + 2 H + 1L + 3M 1HS If you had 10 slices of bread, 7 slices of ham and unlimited lettuce and mustard: a) Which reactant is limiting? b) Which reactant is in excess and by how much? c) How many ham sandwiches could you make? a) 4 mol B = 2 mol H 10 mol B x 2 mol H 7 mol H x 4 mol B 4 mol B 2 mol H = 5 mol H = 14 mol B Therefore bread is limiting b) 7 mol H 5 mol H = 2 mol H c) 4 mol B = 1 mol HS 10 mol B x 1 mol HS = 2.5 mol HS 4 mol B Heat 1. Circle whether each of the following reactions should be described as exothermic or endothermic. a) Fe 2 O 3 (s) + 3CO (g) 3CO 2 (g) + 2Fe(s) + 25kJ exothermic or endothermic b) 2HCl (g) + 96kJ H 2 (g) + Cl 2 (g) exothermic or endothermic c) 6FeCl 3 (s) 6FeCl 2 (s) + 3 Cl 2 (g) ΔH = +173kJ exothermic or endothermic d) H 2 (g) + Br 2 (g) 2HBr (g) ΔH = -36kJ exothermic or endothermic 2. Does an endothermic reaction absorb heat OR release heat Physics 20 Heat NOTE: You will need to use your tables for linear expansion, heat capacity, heat of fusion and heat of vaporization. 1. Jerry heats a 1.2 m long brass rod from a temperature of 293 K to a temperature of 383 K. Calculate the change in length of the rod. ΔL = L i T (1.2)(19 x 10-6 )(90K) = 2 mm

6 2. You injure your ankle and are given a cold pack. Explain what happens for your ankle to feel cold. When does the flow stop? Are the temperature changes of your ankle and the cold pack equal? The warm particles of your ankle are in contact with the cold particles of the ice pack. The hot particles pass on their energy to the cold particles by colliding with them; this causes the hot particles to slow down (cool down) and the cold particles to speed up (warm up). As a result, over time the particles will reach the same speed and temperature. The temperature will be between the original starting temperatures. 3. When a substance is melting or boiling, what happens to the temperature? Temperature stays the same during a phase change. 4. Does heat flow from high low temp low high temp high low heat low high temperature 5. What is heat of fusion? What is heat of vaporization? The amount of heat required to convert a unit mass of a solid at its melting point into a liquid without an increase in temperature. (Q = mh f ) The heat absorbed by a unit mass of a material at its boiling point in order to convert the material into a gas at the same temperature (Q =mh v ) 6. Energy that flows as a result of a difference in temperature is called? Heat 7. The specific heat of lead is J/g o C. Find the amount of heat released when g of lead are cooled from 37.2 o C to 22.5 o C. Q = mcδt = ( g)(0.129 J/g o C)( 37.2 o C o C) = ( g)(0.129 J/g o C)( 14.7 o C) = J = 943 J 8. When a 120 g sample of aluminum absorbs 9612 J of heat energy, its temperature increases from 25 o C to 115 o C. Find the specific heat of aluminum in J/g o C. Q = mcδt 9612 J = (120 g)(c)(115 o C - 25 o C) 9612 J = (120 g)(c)( 90. o C) c = 0.89 J/kg o C 9. Body temperature is about 36 C. How many Kelvin is this? K = C = = 309 K Waves 10. A machinist finds an aluminum nut locked tightly on a steel bolt. Should the combination be heated or cooled to make it easier to remove the nut? Explain? Heating the pair will cause aluminum ( = 24 x 10-6 ) to expand more than steel ( = 12 x 10-6 ). If they were cooled, aluminum nut would contract more than steel, and it would be locked even more tightly on to the steel bolt. 11. Gallium is one of the few metals that melts near body temperature: its melting point is at about 30 C. The heat of fusion of gallium is 80.4 kj/kg. How much heat is required to melt 150 g of gallium? Q = mh f =(0.15)(80.4) = 12.1 J 1. In a transverse wave the particles of the median vibrate perpendicular to the part along which the wave travels. 2. In a longitudinal wave the particles of the median vibrate parallel to the part along which the wave travels.

7 3. Which of the following is a transverse wave. Label the crests and troughs. What is the line labelled C called? a) is a transverse wave; A crest; B trough; C - equilibrium 4. Which of the following is a longitudinal wave. Label the compressions and rarefactions. b) is a longitudinal wave; B compression; A - rarefaction a) b) 5. A pulse is. Period is. Frequency is.. pulse - is a single disturbance period the time to complete one cycle frequency - the number of events that occur in a certain amount of time. 6. Find the amplitude, wavelength, period, and speed of the 8.0 Hz wave traveling in the diagram. a = 1.3 cm; = 3.15 cm; T = 0.13 s; v = 24 cm/s 7. Two students are testing the information their teacher told them in physics class. They get two pieces of string, and join them as shown in the following diagrams. Both pulses are traveling to the right. A B d) For each scenario, what will happen to the pulse when it REFLECTS BACK FROM the second medium? A upright OR inverted B - upright OR inverted e) For each scenario, what will happen to the pulse when it ENTERS the second medium? A same speed OR slows down OR speeds up B same speed OR slows down OR speeds up 8. Two pulses are traveling in opposite directions along the same medium as shown in the diagram at the right. Which diagram below best depicts the appearance of the medium when each pulse meets in the middle? Diagram D Is this constructive interference OR destructive interference? 9. Label a node. What happens at a node? Letter D, a point on the medium that is staying in the same location Label an antinode. What happens at an antinode? Letter A. vibrates back and forth between a large upward and a large downward displacement 10. A pendulum makes exactly 40 vibrations in 20.0 s. What is its period? a) Hz b) s c) 2.00 Hz d) 2.00 s e) 8.00 x 10 2 Hz 11. The frequency of a wave is increased. What happens to its period? f = 1/T. They are inversely related so if frequency increases, period decreases.

8 12. A wave with a length of 100 m has a period of 2 s. What is the speed of the wave? v = d/t = 100 m 2 s = 50 m/s 13. Calculate the frequency of a wave that has a speed of 4.00 m/s and a wavelength of 3.00 m. f = v/ = 4.00 m/s 3.00 m = 1.33 Hz 14. Once a tsunami wave (and all waves) is produced, it has a fixed frequency as it travels. The wavelength of the wave decreases as it approaches the shore. What happens to the velocity? Decreases 15. A water wave strikes the side of a boat. Will the reflected wave be erect or inverted? Inverted 16. You notice a wave that does not appear to be moving. It has crests that flip into troughs and vice versa. What kind of wave is this? Standing wave Light and Refraction 17. A light ray strikes a plane mirror at an angle of 30.0 from the mirror. a. What is the angle of incidence? 60.0 b. What is the angle of reflection? A student stands 3.0 m in front of a plane mirror. a. If she moves closer to the mirror will she see less of herself? If she moves closer to the mirror she will still see all of herself. b. How large does the mirror need to be to see all of herself? At what height must it be placed? In order to see all of herself, the mirror needs to be half of the student s height. The mirror be placed at eye level. c. How far behind the mirror is her virtual image? 3.0 m d. If she steps forward 1.0 m, what distance will separate her from her virtual image? 4.0 m 19. What occurs to the velocity of a light wave when it travels from air into glass? Would the light bend towards the normal or away from the normal? less more dense, therefore light would bend towards the normal 20. Which will have the larger critical angle when placed in material that is not optically dense water or quartz? Water, which has a smaller index of refraction, causes less refraction than quartz. Therefore, rays in water will be farther from the normal, and it will produce a larger critical angle than quartz. Sin Θ c = 1 n so if n is lower, Θ c will be higher and vice versa. 21. Calculate the index of refraction of a material if the angle of incidence in a vacuum is 60.0 and the angle of refraction is n = sin Θ i sin Θ R = sin60.0 sin50.0 = A transparent substance has an index of refraction of What is the angle of incidence in a vacuum if the angle of refraction in the substance is 22? n = sin Θ i /sin Θ R sin Θ i = n sin Θ R = 1.40(sin 22 ); i = The speed of light in crown glass is 1.97 x 10 8 m/s. If the speed of light in a vacuum is 3.00 x 10 8 m/s, what is the index of refraction of crown glass? n = c v = = 1.52 (exponents cancel) 24. The critical angle for a stone-air boundary is What is the index of refraction of the stone? sin c 1 1 = sin c 1 sin 45.5 = 1.40

9 25. What are the 2 requirements for total internal reflection? 1) The light is in the more dense medium and approaching the less dense medium 2) The angle of incidence is greater than the so-called critical angle Curved Mirrors 26. Label the two mirrors below as either concave or convex. 27. Concave mirrors are silvered on the of a sphere whereas convex mirrors are silvered 28. rical aberration and how can it be avoided? 29. Label the following terms on the diagram below: principle axis, focus, focal length, centre of curvatuf curvature, vertex, mirror. 30. When drawing diagrams for curved mirrors, there are three types of rays that can be drawn. a. If a ray is drawn parallel to the principle axis, where will it pass through? b. If a ray initially goes through the focal point, where will it return? c. If a ray passes through the centre of curvature, where will it return? d. How is the ray different when drawing a real ray vs a virtual ray? 31. Depending on where an object is placed in front of a concave mirror, the image will have varying characteristics. Where must an object be placed in front of a concave mirror for the image to be virtu upright and larger? 32. What are ALWAYS the characteristics of an image formed with a convex mirror? 33. Which side of the convex mirror would be labeled as negative, -? 34. With curved mirrors, f is for a concave mirror and for a convex mirror; di is if the irror). 35. For both mirrors and lenses, if hi is +, the image is, if hi is -, the image is, if m is +, the image is and if m is -, the image is 36. Mirrors and lenses are opposite each other when determining where the image is virtual or real. a. On what side (compared to the object) is an image virtual with a curved mirror? opposite b. On what side (compared to the object) is an image virtual with a curved lens? same 37. A concave/converging mirror is similar to a _convex/converging_ lens in that the image size, attitude and placement will vary depending on where the object is placed. A convex/diverging mirror is similar to a concave/diverging lens in that its image is ALWAYS upright, smaller and virtual. 38. For a convex/converging lens, the primary focus is found on the right side of the lens; for a concave/diverging lens, the primary focus is found on the left side of the lens.

10 39. When light passes through a lens, the ray will bend. This is called refraction. 40. An image in a mirror has the same attitude (direction) as the object in front of a mirror. Could the object be standing in front of a plane mirror? Could it be a convex mirror? What about a concave mirror? The object could be standing in front of a plane mirror but also all images in convex mirrors are erect, and objects that are place between F and V of concave mirrors will be erect. Answer the following FOUR questions based on the following information: The magnification of an image in a mirror is 1.5 times. The focal length of the mirror is +4.0 cm. 41. Is the image upright or inverted? Magnification is positive a) upright b) inverted c) not enough information to determine this 42. Is it larger or smaller than the object? Magnification is greater than 1 a) larger b) smaller c) not enough information to determine this 43. Was the image produced by a concave or convex mirror? Focal length is positive a) concave b) convex c) not enough information to determine this 44. Is the image real or virtual? a) real b) virtual c) not enough information to determine this 45. A baby mouse 1.2 cm high is standing 4.0 cm from a converging mirror having a focal length of 3.0 cm. Find the position and size of its image. 1/3.0 = 1/ /d i d i = 12 cm in front of mirror h i /1.2 = -12/4.0 h i = -3.6 cm so it is inverted 46. Karen holds a ruler 4.0 m from a diverging mirror and sees the ruler one-eighth the normal size. What is the focal length of the mirror? 1/8 = -d i /4.0 d i = -0.5 cm 1/f = 1/ /4.0 f = -4/7 47. What is the meaning of the number and sign if you have a calculated magnification of +0.5? The number indicates how many times larger the image is compared to the object. In this case, the image is 0.5 x or ½ the size of the object. The sign indicates whether the image is erect or inverted. In this case, a positive magnification means that the image is erect. 48. What is the focal length of a diverging mirror with a diameter of 20 cm? Lenses The focal length is half the radius; so it is 5 cm. Properly stated, though, it is f = -5 cm. The negative indicates that it is behind the mirror. 49. Which pair will always produce images with the same properties concave lenses and mirrors or converging lenses and mirrors? Converging describes the direction that light bends. Since light bends in the same direction in converging lenses and mirrors, the images they produce will always have the same characteristics. Concave lenses and mirrors do not produce the same characteristics. 50. What happens to light rays parallel to the principal axis for a converging lens? What about for a diverging lens? For a converging lens, any incident ray traveling parallel to the principal axis of a converging lens will refract through the lens and travel through the focal point on the opposite side of the lens For a diverging lens, Any incident ray traveling parallel to the principal axis of a diverging lens will refract through the lens and travel in line with the focal point (i.e., in a direction such that its extension will pass through the focal point). 51. If the image is a real image which side of the lens will it be located on compared to the object (same or opposite side)? A real image will be on the opposite side of the lens compared to the object. Only convex lenses form real images.

11 52. What does a diverging lens look like? What does a converging lens look like? Diverging lens - Curved in Converging lens Curved out