I need help answering this question. Identify the functional groups.

Calculate [h+] and [oh−] for a neutral solution at this temperature. express your answers using two significant figures. enter y

taurus [48]

When we have Kw = 1.2x10^-15
and according to Kw formula:
Kw = [OH-] [H+]
by substitution:

1.2x10^-15 = [OH-][H+]
when the solution is neutral that means:
[OH-] = [H+]
∴1.2X10^-15 = X^2
∴X = 3.46 x 10^-8
∴[OH-] = [H+] = 3.46x10^-8

4 0

3 years ago

Natural gas burns in air to form carbon dioxide and water, releasing heat. CH4(g)+2O2(g)→CO2(g)+2H2O(g) ΔHrxn = -802.3 kJ.

Olenka [21]

Answer:

1) Minimum mass of methane required to heat 45.0 g of water by 21.0°C is 0.0788 g.

2) Minimum mass of methane required to heat 50.0 g of water by 26.0°C is 0.108 g.

Explanation:

$CH_4(g)+2O_2(g)\rightarrow CO_2(g)+2H_2O(g) ,\Delta H_{rxn} =-802.3 kJ$

1) Minimum mass of methane required to raise the temperature of water by 21.0°C.

Mass of water = m = 45.0 g

Specific heat capacity of water = c = 4.18 J/g°C

Change in temperature of water = ΔT = 21.0°C.

Heat required to raise the temperature of water by 21.0°C = Q

$Q=mc\Delta T= 45.0 g\times 4.18 J/g^oC\times 21.0^oC$

Q = 3,950.1 J = 3.9501 kJ

According to reaction 1 mole of methane on combustion gives 802.3 kJ of heat.

Then 3.950.1 kJ of heat will be given by:

$=\frac{3.950.1 kJ}{802.3 kJ}=0.004923 mol$

Mass of 0.004923 moles of methane :

0.004923 mol × 16 g/mol=0.0788 g

Minimum mass of methane required to heat 45.0 g of water by 21.0°C is 0.0788 g.

2) Minimum mass of methane required to raise the temperature of water by 26.0°C.

Mass of water = m = 50.0 g

Specific heat capacity of water = c = 4.18 J/g°C

Change in temperature of water = ΔT = 26.0°C.

Heat required to raise the temperature of water by 21.0°C = Q

$Q=mc\Delta T= 50.0 g\times 4.18 J/g^oC\times 26.0^oC$

Q = 5,434 J= 5.434 kJ

According to reaction 1 mole of methane on combustion gives 802.3 kJ of heat.

Then 5.434 kJ of heat will be given by:

$=\frac{5.434 kJ}{802.3 kJ}=0.006773 mol$

Mass of 0.006773 moles of methane :

0.006773 mol × 16 g/mol= 0.108 g

Minimum mass of methane required to heat 50.0 g of water by 26.0°C is 0.108 g.

6 0

4 years ago

What is the pH of an aqueous solution of HCl with a hydrogen ion

yulyashka [42]

Answer:

pH = 5.17

Explanation:

pH = -log[H+] = -log(6.7 x 10^-6) = 5.17

6 0

3 years ago

Lewis dot structure of PSI3 with minimized formal charges

vredina [299]

We need to know how many valence electrons are present in a given molecule in order to determine its Lewis dot structure.

<h3>What is Lewis dot structure?</h3>

Lewis dot structure is defined as the visual representation of atoms' electrons using a diagram. It describe the bonds that exist between a molecule's lone pairs of electrons and its atoms.

A lone pair of electrons on the atom with the formal charge of 1- can typically be converted into a bonding pair that is shared with the atom that has the formal charge of 1+ in order to reduce the formal charges when they are present.

Thus, we need to know how many valence electrons are present in a given molecule in order to determine its Lewis dot structure.

To learn more about Lewis dot structure, refer to the link below:

brainly.com/question/20300458

#SPJ1

3 0

2 years ago

Calculate the masses.

malfutka [58]

Answer:

a) Mass = 3.9 g

b) Mass = 0.395 g

Explanation:

Density is related to the mass and volume of a substance by the relation:

$Density = \frac{Mass}{Volume}----(1)$

a) Given:

Volume = 4.00cm3

Density = 0.97 g/cm3

Based on equation (1)

$Mass = density*volume = 0.97 g/cm3*4.00 cm3 =3.9 g$

b) Given:

Volume = 125 ml

Density = 3.16 g/L

1 ml = 0.001 L

Therefore, 125 ml = 0.125 L

Based on equation (1)

$Mass = density*volume = 3.16 g/L*0.125L =0.395 g$

5 0

3 years ago