Which of these elements has four valence electrons

Please help with this practice.

zalisa [80]

C. Bromine is reduced

5 0

3 years ago

I need help with this question ASAP this should have 2 answers

murzikaleks [220]

Answer:

The correct answer is B. and C. according to me!

8 0

3 years ago

Read 2 more answers

Barbiturates are synthetic drugs used as sedatives and hypnotics. Barbital ( = 184.2 g/mol) is one of the simplest of these drug

DanielleElmas [232]

Answer:

118.75°C is the boiling point of a solution.

Explanation:

Mass of the solute that is barbiturates = 42.5 g

Molar mass of a solute = 184.2 g/mol

Moles of solute = $\frac{42.5 g}{184.2 g/mol}=0.2307 mol$

Mass of the solvent that acetic acid = 825 g = 0.825 kg

$molality=\frac{\text{Moles of solute}}{\text{Mass of solvent}}$

Molality of the solution (m):

$m=\frac{0.2307 mol}{0.825 kg}=0.2796 m$

Elevation in boiling point is given as:

$\Delta T_b=i\times K_b\times m$

i = 1 (organic compound)

$=1\times 3.07^oC/m\times 0.2796 m=0.8585^oC$

$\Delta T_b=T_b-T$

$T_b$ = Boiling temperature of solution.

T = boiling temperature of solvent that is acetic acid=117.9°C

$0.8585^oC=T_b-117.9^oC$

$T_b=118.75 ^oC$

118.75°C is the boiling point of a solution.

6 0

3 years ago

A brick has dimensions of 15 cm by 6.0 CM by 12 CM what is the volume of the brick in cubic meters

VLD [36.1K]

The volume of the brick in cubic meters is 0.00108 m³

calculation

volume of a brick =length x width x height

-length = 15 cm

width = 6.0 cm

height = 12 cm

volume is therefore= 15 cm x 6.0 cm x 12 cm =1080 cm³

convert 1080 cm³ into m³

that is 1 cm³ = 1 x 10^-6m³

1080 cm³ = ? m³

by cross multiplication

=[ (1080 cm³ x 1 x10^-6 m³) / 1 cm³] = 0.00108 m³

7 0

3 years ago

What mass of nitrogen monoxide is formed in the reaction of 869kg ammonia and 2480kg oxygen gas? (Please show work)

USPshnik [31]

Answer:

1533.6 kg NO

Explanation:

The reaction that takes place is:

4NH₃ + 5O₂ → 4NO + 6H₂O

First we convert the masses of ammonia (NH₃) and oxygen gas (O₂) into moles, using their respective molar masses:

NH₃ ⇒ 869 kg ÷ 17 kg/kmol = 51.12 kmol NH₃

O₂ ⇒ 2480 kg ÷ 32 kg/kmol = 77.5 kmol O₂

77.5 kmol of O₂ would react completely with (77.5 kmol O₂ * $\frac{4kmolNH_3}{5kmolO_2}$ ) 62 kmol of NH₃. There are not as many kmol of NH₃, so NH₃ is the limiting reactant.

Now we calculate how many kmol of NO are produced, using the limiting reactant moles:

51.12 kmol NH₃ * $\frac{4kmolNO}{4kmolNH_3}$ = 51.12 kmol NO

Finally we convert kmol of NO to mass, using its molar mass:

51.12 kmol NO * 30 kg/kmol = 1533.6 kg NO

6 0

2 years ago