A sample of copper is 5 moles. How many atoms of copper are present?

Perform the following mathematical operation and report the answer to the appropriate number of significant figures. 5.4-4.21

konstantin123 [22]

Answer:

1.2 ( two significant digits)

Explanation:

5.4 - 4.21 answer should only have the the number of significant digits as the number in the equation with the least number of significant digits... in this case 5.4 is only two significant digits....so the answer should only have two significant digits

5.4 - 4.21 = 1.19 round to two digits = 1.2

3 0

11 months ago

You determine the volume of your plastic bag (simulated human stomach) is 1.08 L. How many grams of NaHCO3 (s) are required to f

dsp73

Answer:

3.636 grams of sodium bicarbonate is required.

Explanation:

Using ideal gas equation:

PV = nRT

where,

P = Pressure of gas = 753.5 mmHg = 0.9914 atm

( $1 atm = 760 mmHg$ )

V = Volume of gas = 1.08 L

n = number of moles of gas = ?

R = Gas constant = 0.0821 L.atm/mol.K

T = Temperature of gas = 24.5 °C= 297.65 K

Putting values in above equation, we get:

$(0.9914 atm)\times 1.08 L=n\times (0.0821L.atm/mol.K)\times 297.65K\\\\n=0.0438 mole$

Percentage recovery of carbon dioxide gas = 49.4%

Actual moles of carbon dioxide formed: 49.4% of 0.0438 mole

$\frac{49.4}{100}\times 0.0438 mol=0.02164 mol$

$2NaHCO_3\righarrow Na_2CO_3+H_2O+CO_2$

According to reaction ,1 mol is obtained from 2 moles of sodium bicarbonate.

Then 0.02164 moles f carbon dioxide will be obtained from:

$\frac{2}{1}\times 0.02164 mol=0.04328 mol$

Mass of 0.04328 moles pf sodium bicarbonate:

0.04328 mol × 84 g/mol = 3.636 g

3.636 grams of sodium bicarbonate is required.

5 0

3 years ago

Which of the following most accurately describes a regulatory molecule that must be transported to its place of action within th

Sonbull [250]

Answer:

the answer is hormone

Explanation:

because it is

5 0

2 years ago

A catalyst decreases the activation energy of a particular exothermic reaction by 34 kJ/mol, to 57 kJ/mol. Assuming that the mec

vagabundo [1.1K]

Answer:

the activation energy for the uncatalyzed reverse reaction is 83kJ/mol

Explanation:

see the attached file

4 0

3 years ago

how does an airplane’s kinetic energy and potential energy change as it takes off and lands? How does this energy change relate

mojhsa [17]

Answer: As the airplane goes higher, the mechanical energy is changed into gravitational potential energy. While flying, some energy is lost through drag to thermal (heat) energy and sound energy. Some is also lost as the plane makes the air around it move. ... As speed and height decrease, kinetic and potential energy decrease.

Explanation:

Hope this help

8 0

3 years ago