A new penny has a mass of 2.49 g and a volume of 0.349 cm3. Is the penny made of pure copper?

40

kap26 [50]

Answer:

what you've asked so I guess the answer will be 10 days

8 0

2 years ago

What happens when an electron in its lowest energy level or ground state when it is by absorbs energy?

tester [92]

Explanation:

atom changes from a ground state to an excited state by taking on energy from its surroundings in a process called absorption. The electron absorbs the energy and jumps to a higher energy level. In the reverse process, emission, the electron returns to the ground state by releasing the extra energy it absorbed

8 0

3 years ago

Passing an electric current through a sample of water (H2O) can cause the water to decompose into hydrogen gas (H2) and oxygen g

Lerok [7]

The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.

The reaction for the decomposition of water has been:

$\rm 2\;H_2O\;\rightarrow\;H_2\;+\;O_2$

From the balanced equation, 2 moles of water decomposes to form 1 moles of hydrogen and 1 mole of oxygen.

The mass of oxygen produced has been 50 g. The moles of oxygen has been given by:

$\rm Moles=\dfrac{mass}{molar\;mass}$

The moles of oxygen has been:

$\rm Moles_O_2=\dfrac{50}{32}\;mol\\Moles_O_2=1.5625\;mol$

The moles of oxygen produced has been 1.5625 mol.

The moles of hydrogen decomposed has been given from the balanced chemical equation as:

$\rm 1 \;mole\;O_2=2\;mole\;H_2O\\1.5625\;mol\;O_2=1.5625\;\times\;2\;mol\;H_2O\\1.5625\;mol\;O_2=3.125\;mol\;H_2O$

The moles of hydrogen decomposes has been 3.125 mol.

The mass of hydrogen decomposed has been given by:

$\rm Mass=moles\;times\;molar\;mass\\Mass_{H_2O}=3.125\;\times\;18.01\;g\\Mass_{H_2O}=56.28\;g$

The mass of water decomposed to produce 50 g oxygen has been 56.28 g. Thus, option D is correct.

For more information about moles produced, refer to the link:

brainly.com/question/10606802

8 0

2 years ago

The measure of the number of atoms in one element that will combine with am atom of element is?

raketka [301]

<span>These atoms are known as valence atoms.</span>

4 0

3 years ago

Read 2 more answers

Estimate the Calorie content of 65 g of candy from the following measurements. A 15-g sample of the candy is placed in a small a

GrogVix [38]

Answer:

The calorie content of 65g of candy is 326.78 cal

Explanation:

Step 1: Data given

Mass of the candy = 15.00 grams

Mass of the container = 0.325 kg

Mass of water = 1.75kg

0.624 kg at an initial temperature of 15.0°C.

The specific heat of aluminium = 0.22 Cal/kg°C

The specific heat of water = 1 cal/kg°C

Step 2: Calculate calorie content for a 15 gram sample

ΔQ = Σm*c*ΔT

⇒ m = mass in grams

⇒ with c= the specific heat in Cal/kg°C

⇒ with ΔT = T2 -T1 = the change in temperatures in °C

ΔQ = m(bomb) * C(aluminium) * ΔT + m(cup) * C(aluminium) * ΔT + m(H2O) * c(H20) * ΔT

ΔQ = (m(bomb) + m(cup)) * c(aluminium) + m(H2O)*c(H20) ) * ΔT

⇒ with mass of the bomb calorimeter = 0.325 kg

⇒ with mass of the cup = 0.624 kg

⇒ with c(aluminium) = the specific heat of aluminium = 0.22 Cal/kg°C

⇒ with mass of water = 1.75 kg

⇒ with c(water) = the heat capacity of water = 1 Cal/kg°C

⇒ with ΔT = the change in temperature = T2 - T1 = 53.5 - 15.0 = 38.5 °C

ΔQ = 0.325*0.22*38.5 + 0.624*0.22*38.5 + 1.75*1*38.5

ΔQ = ((0.325 + 0.624)*0.22 + 1.75*1)*38.5

ΔQ = 75.41 cal

Step 3: Calculate the calorie content for a 65 gram sample

For a 65g sample the calorie content will be more or less 4x higher than a 15 gram sample:

ΔQ = 75.41 * (65/15) = 326.78 cal

8 0

3 years ago