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3 years ago

6

Compare the number of valence electrons in an atom of oxygen, o, with the number of valence electrons in an atom of selenium, se

. are oxygen and selenium in the same period or group?

1 answer:

Fiesta28 [93]3 years ago

4 0

Oxygen and selenium both have 6 valence electrons. They're in the same group hope this helps

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When 3.51 g of phosphorus was burned in chlorine, the product was a phosphorus chloride. Its vapor took 1.77 times as long to ef

kumpel [21]

Answer:

<em>molar mass of the phosphorus chloride = 138.06 g/mol</em>

<em></em>

Explanation:

<em>mass of phosphorus will be the same as mass of CO2, since it is stated that they are of equal amount.</em>

mass = 3.51 g

<em>lets assume that it took the CO2 1 sec to effuse, then the time taken by the phosphorus chloride will be 1.77 sec</em>

From this we can say that

rate of effusion of CO2 = 3.51/1 = 3.51 g/s

rate of effusion of the phosphorus chloride = 3.51/1.77 = 1.98 g/s

<em>From graham's equation of effusion</em>,

$\frac{Rc}{Rp}$ = $\sqrt{\frac{Mp\\}{Mc} }$

Rc = rate of effusion of CO2 = 3.51 g/s

Rp = rate of effusion of phosphorus chloride = 1.98 g/s

Mc = molar mass of CO2 = 44.01 g/mol

Mp = molar mass of the phosphorus chloride = ?

Imputing values into the equation, we have

$\frac{3.51}{1.98}$ = $\sqrt{\frac{Mp\\}{44.01} }$

1.77 = $\frac{\sqrt{Mp} }{6.64}$

11.75 = $\sqrt{Mp}$

Mp = $11.75^{2}$

Mp = <em>molar mass of the phosphorus chloride = 138.06 g/mol</em>

5 0

3 years ago

If someone consumes 22 g of sodium chloride per day, what mass (in grams) of sodium does that person consume? Sodium chloride is

kompoz [17]

Answer:

Mass of sodium, the person daily consume = 8.58 g

Explanation:

Given that:-

sodium chloride is 39% sodium by mass which means that:-

100 g of sodium chloride contains 39 g of sodium

Also,

1 g of sodium chloride contains 0.39 g of sodium

So, Given mass = 22 g

22 g of sodium chloride contains $0.39\times 22$ g of sodium

<u>Mass of sodium, the person daily consume = 8.58 g</u>

4 0

4 years ago

Match each definition to the vocabulary word

kirill115 [55]

Answer:

1) prokaryote : no nucleus and is unicellular

2)nucleus : contains genetic information

3) structure: the way it is made

4) eukaryotes : has a nucleus , some are unicellular

5) organelles : perform the different functions the cell need

6) tissue: composed of many cell

7)cell : basic units of Life

8) Mathias schleiden : concluded that all plants are made up of cell

9) Theodore Schwann :concluded all animals are made up of cell

10) Rudolf Virchow : concluded that all cells come from pre-existing cell

5 0

3 years ago

The water-gas shift reaction CO(g)+H2O(g)⇌CO2(g)+H2(g) is used industrially to produce hydrogen. The reaction enthalpy is ΔH∘=−4

denis23 [38]

Answer:

To increase the yield of H₂ we would use a low temperature.

For an exothermic reaction such as this, decreasing temperature increases the value of K and the amount of products at equilibrium. Low temperature increases the value of K and the amount of products at equilibrium.

Explanation:

Let´s consider the following reaction:

CO(g) + H₂O(g) ⇌ CO₂(g) + H₂(g)

When a system at equilibrium is disturbed, the response of the system is explained by Le Chatelier's Principle: <em>If a system at equilibrium suffers a perturbation (in temperature, pressure, concentration), the system will shift its equilibrium position to counteract such perturbation</em>.

In this case, we have an exothermic reaction (ΔH° < 0). We can imagine heat as one of the products. If we decrease the temperature, the system will try to raise it favoring the forward reaction to release heat and, at the same time, increasing the yield of H₂. By having more products, the value of the equilibrium constant K increases.

3 0

3 years ago

What quantity of heat is required to raise the temperature of 460g of aluminum from 15C to 85C?

Hoochie [10]

Answer:

Q = 28.9 kJ

Explanation:

Given that,

Mass of Aluminium, m = 460 g

Initial temperature, $T_i=15^{\circ} C$

Final temperature, $T_f=85^{\circ}$

We know that the specific heat of Aluminium is 0.9 J/g°C. The heat required to raise the temperature is given by :

$Q=mc\Delta T\\\\Q=mc(T_f-T_i)\\\\Q=460\ g\times 0.9\ J/g^{\circ} C\times (85-15)^{\circ} C\\\\Q=28980\ J\\\\\text{or}\\\\Q=28.9\ kJ$

So, 28.9 kJ of heat is required to raise the temperature.

6 0

4 years ago