Predict the ELECTRON and MOLECULAR geometry for a molecule with 5 bonding domains and two lone pairs.

Which reactions are exothermic?

poizon [28]

Answer:

Explanation:

exothermic reactions are the reactions which involve the release of energy.

the energy released can be of any forms ,for example heat,light .

all the combustion reactions are exothermic reactions

4 0

3 years ago

A lead sphere has a mass of 1.20 x 104 g, and its volume is 1.05 x 103 cm^3. Calculate the density of lead.

Hatshy [7]

Answer: The density of lead will be $11.42g/cm^3$

Explanation:

Density is defined as the mass contained per unit volume.

$Density=\frac{mass}{Volume}$

Given : Mass of lead= $1.20\times 10^4g$

Volume of lead = $1.05\times 10^3cm^3$

Putting in the values we get:

$Density=\frac{1.20\times 10^4}{1.05\times 10^3}=11.42g/cm^3$

Thus density of lead will be $11.42g/cm^3$

4 0

3 years ago

Automobile airbags contain solid sodium azide, NaN3, that reacts to produce nitrogen gas when heated, thus inflating the bag. 2N

Vitek1552 [10]

Answer : The value of work done for the system is 1144.69 J

Explanation :

First we have to calculate the moles of $NaN_3$

$\text{Moles of }NaN_3=\frac{\text{Mass of }NaN_3}{\text{Molar mass of }NaN_3}$

Molar mass of $NaN_3$ = 65.01 g/mole

$\text{Moles of }NaN_3=\frac{20.2g}{65.01g/mole}=0.311mole$

Now we have to calculate the moles of nitrogen gas.

The balanced chemical reaction is,

$2NaN_3(s)\rightarrow 2Na(s)+3N_2(g)$

From the balanced reaction we conclude that

As, 2 mole of $NaN_3$ react to give 3 mole of $N_2$

So, 0.311 moles of $NaN_3$ react to give $\frac{0.311}{2}\times 3=0.466$ moles of $N_2$

Now we have to calculate the volume of nitrogen gas.

Using ideal gas equation:

$PV=nRT$

where,

P = Pressure of $N_2$ gas = 1.00 atm

V = Volume of $N_2$ gas = ?

n = number of moles $N_2$ = 0.466 mole

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

T = Temperature of $N_2$ gas = $22^oC=273+22=295K$

Putting values in above equation, we get:

$1.00atm\times V=0.466mole\times (0.0821L.atm/mol.K)\times 295K$

$V=11.3L$

As initially no nitrogen was present. So,

Volume expanded = Volume of nitrogen evolved

Thus,

Expansion work = Pressure × Volume

Expansion work = 1.00 atm × 11.3 L

Expansion work = 11.3 L.atm

Conversion used : (1 L.atm = 101.3 J)

Expansion work = 11.3 × 101.3 = 1144.69 J

Therefore, the value of work done for the system is 1144.69 J

5 0

3 years ago

An increase in the ratio of insulin to glucagon will increase the activity of which of the following enzymes (+ indicates activi

AleksAgata [21]

Answer: An increase in the ratio of insulin to glucagon will increase the activity of --

- Acetyl-CoA carboxylase(+)

-Phosphofructokinase PFK2(+)

-Glycogen synthase(+)

- Hormone sensitive lipase (-). The hormone sensitive lipase activity is not increased with increased insulin activity.

Explanation: increased insulin - glucagon ratio is usually high in fed state.Insulin helps the cells absorb glucose, reducing blood sugar and providing the cells with glucose for energy. When blood sugar levels are too low, the pancreas releases glucagon. Glucagon instructs the liver to release stored glucose, which causes blood sugar to rise.

7 0

3 years ago

Standard 1.11<br> The blue and red parts of the atoms represent the?

andrey2020 [161]

The number of protons in the nucleus for that element

8 0

3 years ago