1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
mel-nik [20]
3 years ago
15

A piece of gold jewelry weighs 11.54 g and has a volume of 0.675 cm3. The jewelry contains only gold (density = 19.3 g/cm3) and

silver (density = 10.5 g/cm3). Assuming that the total volume of the jewelry is the sum of the volumes of the gold and silver that it contains, calculate the percentage of gold in the jewelry.
Chemistry
1 answer:
lbvjy [14]3 years ago
4 0

Answer:

Percentage of gold = 84.6%

Explanation:

Suppose the jewelry has x g of gold and y g of silver

The mass of both is the total mass of the jewelry then:

x + y = 11.54

And as the problem says the total volume is the sum of both volumes.

volume = mass / density

\frac{x}{19.3} + \frac{y}{10.5} = 0.675

Solving the system you get:

x = 9.764 g

y = 1.776 g

The percentage of gold in the jewelry is:

X_{gold} = \frac{9.764}{11.54} * 100 = 84.6\%

You might be interested in
Which processes represent one chemical change in one physical change
prisoha [69]

 decomposition and melting

7 0
3 years ago
Read 2 more answers
Which of the compounds above are strong enough acids to react almost completely with a hydroxide ion (pka of h2o = 15.74) or wit
luda_lava [24]

The compounds can react with OH⁻ and HCO₃⁻ only C₅H₆N pyridinium

<h3><em>Further explanation </em></h3>

In an acid-base reaction, it can be determined whether or not a reaction occurs by knowing the value of pKa or Ka from acid and conjugate acid (acid from the reaction)

Acids and bases according to Bronsted-Lowry

Acid = donor (donor) proton (H + ion)

Base = proton (receiver) acceptor (H + ion)

If the acid gives (H +), then the remaining acid is a conjugate base because it accepts protons. Conversely, if a base receives (H +), then the base formed can release protons and is called the conjugate acid from the original base.

From this, it can be seen whether the acid in the product can give its proton to a base (or acid which has a lower Ka value) so that the reaction can go to the right to produce the product.

The step that needs to be done is to know the pKa value of the two acids (one on the left side and one on the right side of the arrow), then just determine the value of the equilibrium constant

Can be formulated:

K acid-base reaction = Ka acid on the left : K acid on the right.

or:

pK = acid pKa on the left - pKa acid on the right

K = equilibrium constant for acid-base reactions

pK = -log K;

K~=~10^{-pK}

K value> 1 indicates the reaction can take place, or the position of equilibrium to the right.

There is some data that we need to complete from the problem above, which is the pKa value of some compounds that will react, namely:

pyridinium pKa = 5.25

acetone pKa = 19.3

butan-2-one pKa = 19

Let's look at the K value of each possible reaction:

pka H₂O = 15.74, pka of H₂CO₃ = 6.37)

  • 1. C₅H₆N pyridinium

* with OH⁻

C₅H₆N + OH- ---> C₅H₅N- + H₂O

pK = pKa pyridinium - pKa H₂O

pK = 5.25 - 15.74

pK = -10.49

K~=~10^{4.9}

K values> 1 indicate the reaction can take place

* with HCO3⁻

C₅H₆N + HCO₃⁻-- ---> C₅H₅N⁻ + H₂CO₃

pK = 5.25 - 6.37

pK = -1.12

K`=~10^{1.12]

Reaction can take place

  • 2. Acetone C₃H₆O

* with OH-

C₃H₆O + OH⁻ ---> C₃H₅O- + H₂O

pK = 19.3 - 15.74

pK = 3.56

K~=~10^{ -3.56}

Reaction does not happen

* with HCO₃-

C₃H₆O + HCO₃⁻ ----> C₃H₅O⁻ + H₂CO₃

pK = 19.3 - 6.37

pK = 12.93

K`=~10 ^{-12.93}

Reaction does not happen

  • 3. butan-2-one C₄H₇O

* with OH-

C₄H₇O + OH- ---> C₄H₆O- + H₂O

pK = 19 - 15.74

pK = 3.26

K~=~10^{-3.26}

Reaction does not happen

* with HCO₃⁻

C₄H₇O + HCO₃⁻ ---> C₄H₆O⁻ + H₂CO₃

pK = 19 - 6.37

pK = 12.63

K~=~ 10^{-12.63}

Reaction does not happen

So that can react with OH⁻ and HCO₃⁻ only C₅H₆N pyridinium

<h3><em>Learn more </em></h3>

the lowest ph

brainly.com/question/9875355

the concentrations at equilibrium.

brainly.com/question/8918040

the ph of a solution

brainly.com/question/9560687

Keywords : acid base reaction, the equilibrium constant

5 0
3 years ago
Read 2 more answers
What is the gram-formula mass of Fe(NO3)3?
dusya [7]
M Fe = 55,85g ≈ 56g
m O = 16g
m N = 14g
m Fe(NO3)3 = 56g + 3*14g + 3*3*16g = 242g/mol

answer: (4)
8 0
3 years ago
Read 2 more answers
Construct <br> an isotope has 17 protons 20 neutrons and 18 electrons
ASHA 777 [7]
Add proton + neutrons = Mass 37

Proton is same as your atomic mass= 17

If you go on the periodic table look up 17 and it will give u the letter.
4 0
2 years ago
Which element forms a chloride of the type XCl2
Nat2105 [25]

Explanation:

Element X forms a chloride with the formula XCl 2 , which is a solid with a high melting point. X would most likely be in the same group of the Periodic Table as. (a) Na (b) Mg (c) Al (d) Si. the answer is Mg .

8 0
2 years ago
Other questions:
  • How to calculate the mass of solid sodium hydroxide needed to prepare 200 ml of a 0.040m solution. if one pellet of sodium hydro
    8·1 answer
  • The combustion of titanium with oxygen produces titanium dioxide: Ti(s) + O2(g) → TiO2(s) When 2.060 g of titanium is combusted
    9·1 answer
  • What happens to the DNA during interphase?
    5·2 answers
  • How do you think energy flows in and out of the earth's atmosphere ?
    10·1 answer
  • Why is the separation of waste rock before mining so important?​
    7·1 answer
  • How many molecules of N2O5 are there in 175 grams of N2O5?
    11·1 answer
  • I’m confused how to do this
    5·1 answer
  • Which upgrade to a school will most likely reduce the school's consumption of
    11·1 answer
  • What is the pH of a 1.0 x 102 M solution of HNO,?
    12·1 answer
  • As the frequency of a wave increases, what happens to the energy the wave is carrying?
    11·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!