When 45.8 g of K2CO3 react with excess HCI, 46.3 g of KCl are formed. Calculate the theoretical and % yields of

What happens to the molecules that make up a chocolate chip as it is heated in the oven?

Aloiza [94]

Answer:As thermal energy is transferred to the chocolate, its molecules vibrate faster and faster. Eventually they vibrate fast enough that they start to slide past each other and move around. As this happens, the chocolate changes from a solid to a liquid.

Explanation:

5 0

2 years ago

Read 2 more answers

The ratio of carbon-14 to carbon-12 in a piece of charcoal from a fire pit in an archaeological excavation is found to be 12.5%

blagie [28]

Answer:

17190 years

Explanation:

The exponential decay equation is:

$N_{t} = N_{0}e^{-\lambda t}$

$\frac{N_{t}}{N_{0}} = e^{-\lambda t}$

Where:

N(t) is the quantity at time t

N₀ is the initial amount

λ is the decay constant = ln(2)/t(1/2)

t(1/2) is the half-life

Since the ratio of carbon-14 to carbon-12 is 12.5%, we have that:

$\frac{N_{t}}{N_{0}} = e^{-\lambda t}$

$\frac{0.125N_{0}}{N_{0}} = e^{-\lambda t}$

$ln(0.125) = -\lambda t$

By solving the above equation for t:

$t = \frac{ln(0.125)}{-\lambda} = \frac{ln(0.125)}{-ln(2)/t_{1/2}} = \frac{5730 y* ln(0.125)}{-ln(2)} = 17190 y$

Therefore, the site is 17190 years old.

I hope it helps you!

3 0

2 years ago

Predict which atom has a higher ionization energy. CL or I

bija089 [108]

I'm pretty sure your answer is CL.

7 0

3 years ago

Read 2 more answers

Im sorry if its difficult to read

anzhelika [568]

Answer:

A ball is thrown straight up from a rooftop 320 feet high. The formula below describes the ball's height above the ground, h, in feet, t seconds after it was thrown. The ball misses the rooftop on its way down and eventually strikes the ground. How long will it take for the ball to hit the ground? Use this information to provide tick marks with appropriate numbers along the horizontal axis in the figure shown.

h=-16t^2+16t+320

6 0

3 years ago

In the copper – silver nitrate lab Copper medals and silver nitrate solution reacted to produce silver metal and copper (II) nit

Nataly [62]

Answer:

Percent Yield = 97.75 %

Explanation:

1 MOLE = It is equal to the molar mass of the substance

1 mole of Cu = 63.54 g (Molar Mass of Cu = 63.54 g/mole)

1 mole of AgNO3 = 170 g (Molar Mass of AgNO3 = 170 g/mol)

Given Mass of AgNO3 = 1.41 g

Given Mass of Cu = 2.93 g

<em><u>Second step : Find the limiting Reagent (which is in less amount) </u></em>

Balanced Chemical equation :

$Cu + 2AgNO_{3} \rightarrow Cu(NO_{3})_{2}+2Ag$

This means

1 mole of Cu will react with = 2 mole of AgNO3

63.54 g of Cu reacts with = 2 x 170 g of AgNO3

1 g of Cu reacts with = (2 x 170)/63.54 of AgNO3

$= \frac{170\times 2}{63.54}$

= 5.35 g of AgNO3

2.93 g should reacts with = 2.93 x 5.35 = 15.67 g of AgNO3

Available AgNO3 = 1.41 g

So , AgNO3 is less than required = limiting reagent

Now the reaction occur 1.41 g of AgNO3

Now, Limiting reagent will decide How much Silver(Ag) Metal will form

2 mole of AgNO3 will produce = 2 mole of Ag

1 mole of AgNO3 will produce = 1 mole of Ag

170 g AgNO3 will produce = 107.86 mole of Ag(Molar mass of Ag = 107.86)

1 g AgNO3 will produce =

$\frac{107.86}{170}$

1.41 g of AgNO3 will produce =

$\frac{107.86\times 1.41}{170}$

= 0.89 g

$Yield\ Percent = \frac{Actual\ Yield}{Theoritical\ Yield}\times 100$

Actual yield = 0.87 g

Theoritical yield = 0.89 g

$Yield\ Percent = \frac{0.87}{0.89}\times 100$

Percent Yield = 97.75 %

5 0

3 years ago