Bridge Notation
Convert 0.0450 km to m.
45.0 m
Mass = 41.4 g and volume = 18.0 mL. Find the density.
2.30 g/mL
How many significant figures are in 0.09080?
4 sig figs:
9, 0, 8, and the final 0
Copper wire is bent into a coil. Classify and defend it.
Physical: the copper remains the same substance
Accepted value = 50.0. Trials: 49.9, 50.1, 50.0. Describe the results.
Both accurate and precise
Convert 18 degrees C to K.
291 K
Convert 1.85 g to mg.
1.85 x 103 mg
Density = 8.40 g/mL and volume = 6.50 mL. Find mass.
54.6 g
Which digits are significant in 0.02030?
2 significant digits:
The sandwiched 0, 3, and the final 0
Silver becomes tarnished after reacting with sulfur compounds. Classify and defend it.
Chemical: tarnish is new material on the surface
Accepted value = 100. Trials: 92.1, 92.0, 92.2. Describe the results.
High precision, low accuracy
Convert 95 degrees F to degrees C.
35 degrees C
Convert 14.5 in to cm.
36.8 cm
Mass = 72.0 g and density = 6.00 g/mL. Find volume.
12.0 mL
Round 7.36 + 0.8 + 12.005 correctly.
20.2
A liquid is flammable. What kind of property is this?
Chemical property: it describes combustion reactivity
Experimental = 23.4 and accepted = 24.0. Percent error?
2.5%
Convert 295 K to degrees C.
22 degrees C
Convert 7.25 ft to m.
2.21 m
Water rises from 18.5 mL to 27.3 mL. The solid mass is 70.4 g. Find density.
8.0 g/mL
Round (6.40 x 2.25) / 3.0 correctly.
4.8
Sugar dissolves in water, then crystals are recovered after evaporation. What kind of change?
Physical: the sugar identity is retained and recoverable
Experimental = 47.2 and accepted = 45.0. Percent error?
4.89%
Object A is 80 degrees C, and object B is 20 degrees C. Which way does heat transfer?
From A to B until thermal equilibrium
Convert 1.80 gal to mL.
6.81 x 103 mL
A 0.125 kg sample has a volume of 50.0 mL. Find the density in g/mL.
2.50 g/mL
A student reports 7.5 / 3.0 = 2.500
What should it be, and why?
2.5, because the answer needs 2 significant figures
Two solutions form a solid, and the cup gets warmer. What evidence matters?
Solid formation plus temperature change indicate a reaction
Trials are 5, 10, and 15, while the accepted = 10. What is the accuracy/precision issue?
The average is accurate, but the trials are not precise
Convert 50 degrees C to degrees F.
122 degrees F