True or False: if chemicals behave in a similar way they are grouped together on the periodic table

When heat is applied to 80 grams of CaCO3, it yields 39 grams of CO2. Determine

galben [10]

Answer: The percentage yield of $CO_2$ is 90.26%.

Explanation:

The number of moles is defined as the ratio of the mass of a substance to its molar mass. The equation used is:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ ......(1)

Given mass of $CaCO_3$ = 80 g

Molar mass of $CaCO_3$ = 100 g/mol

Plugging values in equation 1:

$\text{Moles of }CaCO_3=\frac{80g}{100g/mol}=0.8 mol$

For the given chemical equation:

$CaCO_3\rightarow CaO+CO_2$

By the stoichiometry of the reaction:

If 1 mole of $CaCO_3$ produces 1 mole of $CO_2$

So, 0.8 moles of $CaCO_3$ will produce = $\frac{1}{1}\times 0.8=0.8mol$ of $CO_2$

Molar mass of $CO_2$ = 44 g/mol

Plugging values in equation 1:

$\text{Mass of }CO_2=(0.8mol\times 44g/mol)=35.2g$

The percent yield of a reaction is calculated by using an equation:

$\% \text{yield}=\frac{\text{Actual value}}{\text{Theoretical value}}\times 100$ ......(2)

Given values:

Actual value of $CO_2$ = 35.2 g

Theoretical value of $H_2CO_3$ = 39 g

Plugging values in equation 2:

$\% \text{yield of }CO_2=\frac{35.2g}{39g}\times 100\\\\\% \text{yield of }CO_2=90.26\%$

Hence, the percentage yield of $CO_2$ is 90.26%.

8 0

3 years ago

Enter your answer in the provided box. The atomic masses of 63Cu (69.17 percent) and 65Cu (30.83 percent) are 62.94 and 64.93 am

dybincka [34]

Answer: The average atomic mass of copper is 63.55 amu.

Explanation:

Average atomic mass of an element is defined as the sum of masses of each isotope each multiplied by their natural fractional abundance.

Formula used to calculate average atomic mass follows:

$\text{Average atomic mass }=\sum_{i=1}^n\text{(Atomic mass of an isotopes)}_i\times \text{(Fractional abundance})_i$ .....(1)

For $_{29}^{63}\textrm{Cu}$ isotope:

Mass of $_{29}^{63}\textrm{Cu}$ isotope = 62.94 amu

Percentage abundance of $_{29}^{63}\textrm{Cu}$ = 69.17 %

Fractional abundance of $_{29}^{63}\textrm{Cu}$ isotope = 0.6917

For $_{29}^{65}\textrm{Cu}$ isotope:

Mass of $_{29}^{65}\textrm{Cu}$ isotope = 64.93 amu

Percentage abundance of $_{29}^{65}\textrm{Cu}$ = 30.83 %

Fractional abundance of $_{29}^{65}\textrm{Cu}$ isotope = 0.3083

Putting values in equation 1, we get:

$\text{Average atomic mass of Copper}=[(62.94\times 0.6917)+(64.93\times 0.3083)]\\\\\text{Average atomic mass of copper}=63.55amu$

Hence, the average atomic mass of copper is 63.55 amu.

4 0

3 years ago

Where is enery convert to a more usabled form in a process called cellular respiration?

kari74 [83]

Adenosine triphosphate is the correct answer

7 0

4 years ago

When the temperature of a gas changes, it's volume decreases from 12 cm3 to 7 cm3 if the final temperature is measured to be 18°

ElenaW [278]

Answer:

The initial temperature is 499 K

Explanation:

Step 1: Data given

initial volume = 12 cm3 = 12 mL

Final volume = 7 cm3 = 7mL

The final temperature = 18 °C = 291 K

Step 2: Calculate the initial temperature

V1/T1 = V2/T2

⇒with V1 = the initial volume = 0.012 L

⇒with T1 = the initial volume = ?

⇒with V2 = the final volume 0.007 L

⇒with T2 = The final temperature = 291 K

0.012 / T1 = 0.007 / 291

0.012/T1 = 2.4055*10^-5

T1 = 0.012/2.4055*10^-5

T1 = 499 K

The initial temperature is 499 K

8 0

3 years ago

Help pls What have you taken away from the work of Stephen Hawking?

Ivahew [28]

When Stephen Hawking was diagnosed with ALS at age 21, he knew he had little time left. But he also knew he wanted to do so much more first. With these circumstances, he learned the importance of carpe diem .

8 0

3 years ago

True or False: if chemicals behave in a similar way they are grouped together on the periodic table​

True or False: if chemicals behave in a similar way they are grouped together on the periodic table