In an old trunk, you find a piece of metal that you think may be ...

Question

In an old trunk, you find a piece of metal that you think may be aluminum, silver, or lead. You take it to a lab, where you find it has a mass of 217 g and a volume of 19.2 cm³. Using TABLE 2.8, what is the metal you found?

Accepted Answer

Welcome back everyone. A block of metal has a mass of 173 g and a volume of 19.4 cubic centimeters. What is the identity of the metal? We have choice A which states that it's copper with a density of 8.92 g per milliliter. Choice B states iron with a density of 7.86 g per milliliter. Choice C states gold with a density of 19.3 g per milliliter and choice D states aluminum with a density of 2.70 g per milliliter. Let's recall that density is expressed by our symbol row and has units as we see of grams per milliliter and is found from taking our mass divided by volume in the denominator. So let's begin by plugging in what we know to find the density of our unknown metal. However, note that the given volume is in units of cubic centimeters and because our density should be grams per mil liter, we want to take our volume of 19. cubic centimeters and multiply by a conversion factor to go from centimeters in the denominator to milliliters in the numerator And so let's recall that we actually have for one cc an equivalent of one mL in the numerator. So we can cancel out cubic centimeters and we're left with milliliters as our final unit of volume. So when we simplify, we'll find our volume of our unknown metal in ml as 19.4 ml. So now going back to our density formula, we would set this equal to in our numerator, we have our mass of 173 g as given in the prompt divided by our volume from above in milliliters as 19.4 mL in the denominator. So when we get the results, we're going to find that our density of our unknown metal is equal to a value of 8.9 to grams per milliliter. And looking at our answer choices, we can see that this density corresponds to choice A as our final answer which states that the identity of the metal is copper. So I hope that this made sense and let us know if you have any questions.

In an old trunk, you find a piece of metal that you think may be aluminum, silver, or lead. You take it to a lab, where you find it has a mass of 217 g and a volume of 19.2 cm³. Using TABLE 2.8, what is the metal you found?

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