Chemistry

Gold is alloyed with other metals to increase its hardness in making jewelry.

Consider a piece of gold jewelry that weighs 9.85 g and has a colume of 0.675 cm cubed. The jewelry contains only gold and silver, which have densities of 19.3 g/cm cubed and 10.5 g/cm cubed, respectively. Assuming that the total colume of the jewelry is the sum of the columes of the gold and silver that it contains, calculate the percentage of gold (by mass) in the jewelry.

The answer is 61.5% Au, but I have no idea whatsoever how to find that answer...


massgold + massmetal= totalmass

you are given the total mass.
Volumegold + volumemetal= total volume
you are given the total volume

from the first...
massgold + massmetal= totalmass
densitygold*volumegold + densitymetal*volumemetal=9.85

So now you have two equations:

Volumegold + volumemetal=.675
19.3*volumegold + 10.5*volumemetal=9.85

solve for the volume of gold (any method you choose..I recommend substution)
Then, solve for the mass of gold from volume and density, then finally, percentage.

Repost if you get stuck. Nice problem


THANKS FOR YOUR HELP
Can I have your age AND EMAIL ADDRESS PLEASE. i REALLY WAS STUCK ON FUR SEALS.
tHANKS STEPH

  1. 👍 0
  2. 👎 0
  3. 👁 282

Respond to this Question

First Name

Your Response

Similar Questions

  1. Algebra

    The purity of gold is measured in karats. Twenty-four karat gold is pure gold and k karat gold is k/24 gold by mass. One piece of 16-karat gold jewelry has a mass of 30 grams and another piece of 10-karat gold jewelry has a mass

    asked by Laur on January 26, 2011
  2. Algebra 2

    The purity of gold is measured in karats. Twenty-four karat gold is pure gold and k karat gold is k/24 gold by mass. One piece of 16-karat gld jewelry has a mass of 30 grams and another piece of 10-karat gold jewelry has a mass of

    asked by Jay on January 30, 2011
  3. Chemistry

    Consider a piece of gold jewelry that weighs 9.81 g and has a volume of 0.670 cm3. The jewelry contains only gold and silver, which have densities of 19.3 g/cm3 and 10.5 g/cm3, respectively. Assuming that the total volume of the

    asked by Anonymous on August 18, 2013
  4. science

    Consider a piece of gold jewelry that weighs 9.35 g and has a volume of 0.690 cm3 . The jewelry contains only gold and silver, which have densities of 19.3 g/cm3 and 10.5 g/cm3, respectively. If the total volume of the jewelry is

    asked by Mikel on July 15, 2017
  5. Chemistry

    From the jewelry descriptions given, select the homogeneous mixture or solution. Answer?? 10 carat (K) electroplated gold jewelry 24 carat (K) gold jewelry (i know this is pure gold) 18 carat (K) gold jewelry Are these right?

    asked by Lucky on January 28, 2013
  6. chemistry

    From the jewelry descriptions given, select the homogeneous mixture or solution. Answer?? 10 carat (K) electroplated gold jewelry 24 carat (K) gold jewelry (i know this is pure gold) 18 carat (K) gold jewelry Are these right?

    asked by Lucky on January 28, 2013
  7. Chemistry

    Pure platinum is too soft to be used in jewelry because it scratches easily. To increase the hardness so that it can be used in jewelry, platinum is combined with other metals to form an alloy. To determine the amount of platinum

    asked by Pauline on March 14, 2018
  8. HELP MATH

    Annna wants to buy her grandmother a gift. Anna decides to buy a piece of jewelry. At the store she sees that 1/2 of the jewelry is necklaces. 1/4 of the jewelry is pins. The rest of the jewelry is a total of 16 bracelets and

    asked by Please Please Help on November 15, 2009
  9. Chemistry - radioactive decay .

    list 2 reason why this isotope of gold- 191 would not be a good substitute for making jewelry?

    asked by Maria on September 18, 2012
  10. Chemistry

    Some pieces of jewelry react with compounds in sweat. The reaction can leave stains on your skin. Not all jewelry has this effect. Use the activity series of metals to explain this observation. please help

    asked by HolfBrincl on October 25, 2016

More Similar Questions