4 Part A A graduated cylinder contains 145 mL of water. A 19.0 g piece of iron (density = 7.86 g/cm³) and a 18.0 g piece of lead (density = 11.3 g/cm³) are added. What is the new water level, in milliliters, in the cylinder? Express your answer to three significant figures.

A person weighed 15 pennies on a balance and recorded the following masses: 3.112 g 3.109 g 3.059 g 2.467 g 3.079 g 2.518 g 3.129 g 2.545 g 3.050 g 3.053 g 3.054 g 3.072 g 3.081 g 3.131 g 3.064 g Curious about the results, he looked at the dates on each penny. Two of the light pennies were minted in 1983 and one in 1982. The dates on the 12 heavier pennies ranged from 1970 to 1982. Two of the 12 heavier pennies were minted in 1982. a. Do you think the Bureau of the Mint changed the way it made pennies? Explain. b. The person calculated the average mass of the 12 heavy pennies. He expressed this average as 3.0828 g 0.0482 g. What is wrong with the numbers in this result, and how should the value be expressed?

A sample of a bright blue mineral was weighed in air, then weighed again while suspended in water. An object is buoyed up by the mass of the fluid displaced by the object. In air, the mineral weighed 7.35 g; in water, it weighed 5.40 g. The densities of air and water are 1.205 g/L and 0.9982 g/cm3, respectively. What is the density of the mineral?

In each case, decide if the underlined property is a physical or chemical property. (a) The color of elemental bromine is orange-red. (b) Iron turns to rust in the presence of air and water. (c) Hydrogen can explode when ignited in air (Figure 1.16). (d) The density of titanium metal is 4.5 g/cm3. (e) Tin metal melts at 505 K. (f) Chlorophyll, a plant pigment, is green.

Express the measurements to the requested number of significant figures. (a) 96,485 J/C to three significant figures (b) 2.9979 g/cm3 to three significant figures (c) 0.0597 mL to one significant figure (d) 6.626 1034 kg to two significant figures

An aqueous stock solution is 85.0% H3PO4 by mass and its density is 1.69 g/mL. What volume of this solution is required to make 1.25 L of 2.55 mol/L H3PO4(aq)? Give your answer in millilitres, accurate to three significant figures.  Enter the correct symbol for millilitres in the units box.

Tums is a popular remedy for acid indigestion. A typical Tums tablet contains calcium carbonate mixed with inert substances. When ingested, it reacts with stomach acids (hydrochloric acid) to produce carbon dioxide gas. When a 1.201 g Tums tablet reacted with 42.035 mL of hydrochloric acid (density: 1.140 g/mL), carbon dioxide gas was produced and the resulting solution weighed 48.941 g. Calculate the mass of carbon dioxide gas released. Calculate the volume of carbon dioxide gas released. The density of carbon dioxide is 1.18 g/L

The water level in a graduated cylinder is initially at 225 mLmL and rises to 285 mLmL after a piece of lead is submerged. What is the mass, in grams, of the lead  (D=11.3g/mLD=11.3g/mL)? Express your answer to two significant figures and include the appropriate units.

Iron pyrite is often called “fool’s gold” because it looks like gold. Suppose you have a solid that looks like gold which has a mass of 23.5g. When the sample is immersed into the water in a graduated cylinder, the water level rises from 47.5 ml to 52.2 ml. is this sample a “fool’s gold” or “real” gold? (Hint: density = 5.00 g/cm3 for fool’s gold and real gold is density = 19.3 g/cm3)

A chemist prepares a solution of copper(II) sulfate (CuSO4) by weighing out 9.472 g of copper(II) sulfate into a 50. mL volumetric flask and filling the flask to the mark with water. Calculate the concentration in g/L of the chemist's copper(II) sulfate solution. Be sure your answer has the correct number of significant digits. ? 10 x10 X Ś A alo