I need help!!!! Plz help me with the above question

A substance that contains various elements or compounds without bonding or fixed proportions is a(n) _____.

Flauer [41]

Is a mixture! .......

8 0

3 years ago

Read 2 more answers

Which bonds are found inside a water molecule, between hydrogen and oxygen?

Papessa [141]

Hydrogen bond is found between water molecule if im correct

5 0

3 years ago

When 1.045 g of CaO is added to 50.0 mL of water at 25.0 °C in a calorimeter, the temperature of the water increases to 32.3 °C.

Rus_ich [418]

Answer:

1.71 kJ/mol

Explanation:

The expression for the calculation of the enthalpy change of a process is shown below as:-

$\Delta H=m\times C\times \Delta T$

Where,

$\Delta H$ is the enthalpy change

m is the mass

C is the specific heat capacity

$\Delta T$ is the temperature change

Thus, given that:-

Mass of CaO = 1.045 g

Specific heat = 4.18 J/g°C

$\Delta T=32.3-25.0\ ^0C=7.3\ ^0C$

So,

$\Delta H=1.045\times 4.18\times 7.3\ J=31.88713\ J$

Also, 1 J = 0.001 kJ

So,

$\Delta H=0.03189\ kJ$

Also, Molar mass of CaO = 56.0774 g/mol

$Moles=\frac{Mass}{Molar\ mass}=\frac{1.045}{56.0774}\ mol=0.01863\ mol$

Thus, Enthalpy change in kJ/mol is:-

$\Delta H=\frac{0.03189}{0.01863}\ kJ/mol=1.71\ kJ/mol$

8 0

2 years ago

In a room full of air, the air is mainly composed of Nitrogen and Oxygen molecules (both at room temperature). Find (to two sign

zloy xaker [14]

Explanation:

Expression for the $v_{rms}$ speed is as follows.

$v_{rms} = \sqrt{\frac{3kT}{M}}$

where, $v_{rms}$ = root mean square speed

k = Boltzmann constant

T = temperature

M = molecular mass

As the molecular weight of oxygen is 0.031 kg/mol and R = 8.314 J/mol K. Hence, we will calculate the value of $v_{rms}$ as follows.

$v_{rms} = \sqrt{\frac{3kT}{M}}$

= $\sqrt{\frac{3 \times 8.314 J/mol K \times 309.02 K}{0.031 kg/mol}}$

= 498.5 m/s

Hence, $v_{rms}$ for oxygen atom is 498.5 m/s.

For nitrogen atom, the molecular weight is 0.028 kg/mol. Hence, we will calculate its $v_{rms}$ speed as follows.

$v_{rms} = \sqrt{\frac{3kT}{M}}$

= $\sqrt{\frac{3 \times 8.314 J/mol K \times 309.92 K}{0.028 kg/mol}}$

= 524.5 m/s

Therefore, $v_{rms}$ speed for nitrogen is 524.5 m/s.

3 0

3 years ago

Determine the electron-group arrangement, molecular shape, and ideal bond angle(s) for each of the following:

antoniya [11.8K]

The electron group arrangement of PH₃ is tetrahedral. The molecular shape is a Trigonal pyramid, and the bond angle is 93°.

<h3>What is the bond angle?</h3>

The angle between the atoms in a compound is known as the bond angle. The degree of the binding angle is specified. There is also the bond length. It is the separation between the two atoms' nuclei.

The bond angle between the atoms of phosphine is 93°. It has one lone pair. The central atom is covered with 4 atoms.

Thus, the electron-group arrangement of phosphine is tetrahedral. The molecular geometry or shape is a trigonal pyramid. The bond angle is 93°.

To learn more about bond angles, refer to the link:

brainly.com/question/1851495

#SPJ4

8 0

2 years ago