What type of wave is shown ?

What is the mass in grams of 9.76 x 10 12 atoms of naturally occurring sodium?

Fiesta28 [93]

The number of moles in a substance indicates the amount of the substance that contains the same number of particles as 12 g of the Carbon-12 isotope [or equivalent to 6.02 × 10²³] (which is used as a standard in the world of moles).

Now,

if 6.02 × 10²³ atoms are found in 1 mole ofsodium
then let 9.76 × 10¹² atoms are found in x

⇒ x = (9.76 × 10¹² ) ÷ (6.02 × 10²³)

= 1.619 × 10⁻¹¹ mol

Now, mass = moles × molar mass

∴ mass of Na = 1.619 × 10⁻¹¹ mol × 23 g/mol
= 3.72 × 10⁻¹⁰ g

4 0

3 years ago

Phosphorous pentoxide, P2O5(s), is produced from the reaction between pure oxygen and pure phosphorous (P, solid). What is the v

BartSMP [9]

Answer:

4190.22 L = 4.19 m³.

Explanation:

For the balanced reaction:

2P₂ + 5O₂ ⇄ 2P₂O₅.

It is clear that 2 mol of P₂ react with 5 mol of O₂ to produce 2 mol of P₂O₅.

Firstly, we need to calculate the no. of moles of 6.92 kilograms of P₂O₅ produced through the reaction:

no. of moles of P₂O₅ = mass/molar mass = (6920 g)/(283.88 g/mol) = 24.38 mol.

Now, we can find the no. of moles of O₂ is needed to produce the proposed amount of P₂O₅:

Using cross multiplication:

5 mol of O₂ is needed to produce → 2 mol of P₂O₅, from stichiometry.

??? mol of O₂ is needed to produce → 24.38 mol of P₂O₅.

∴ The no. of moles of O₂ needed = (5 mol)(24.38 mol)/(2 mol) = 60.95 mol.

Finally, we can get the volume of oxygen using the general law of ideal gas: PV = nRT.

where, P is the pressure of the gas in atm (P = 606.1 mm Hg/760 = 0.8 atm).

V is the volume of the gas in L (V = ??? L).

n is the no. of moles of the gas in mol (n = 60.95 mol).

R is the general gas constant (R = 0.0821 L.atm/mol.K),

T is the temperature of the gas in K (396.90°C + 273 = 669.9 K).

∴ V of oxygen needed = nRT/P = (60.95 mol)(0.0821 L.atm/mol.K)(669.9 K)/(0.8 atm) = 4190.22 L/1000 = 4.19 m³.

3 0

3 years ago

Which of the following would become a negative ion before bonding?

Anarel [89]

Isn't it nitrogen AND chlorine? Both are nonmetals, and they need to gain electrons in order to bond.

7 0

3 years ago

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The balanced equation for combustion in an acetylene torch is shown below: 2C2H2 + 5O2 → 4CO2 + 2H2O The acetylene tank contains

andriy [413]

Answer: 67.2 moles

Explanation: $2C_2H5+5O_2\rightarrow 4CO_2+2H_2O$

According to the given balanced equation, 2 moles of acetylene $C_2H_2$ combine with 5 moles of oxygen $O_2$ to produce 4 moles of carbon dioxide $CO_2$ .

Thus if 2 moles of acetylene $C_2H_2$ combine with = 5 moles of oxygen $O_2$

35 moles of acetylene $C_2H_2$ combine with= $\frac{5}{2}\times {35}=87.5$ moles of oxygen $O_2$

But as only 84 moles of oxygen are available, acetylene is not a limiting reagent.

5 moles of oxygen $O_2$ reacts with = 2 moles of acetylene $C_2H_2$

84 moles of oxygen $O_2$ reacts with= $\frac{2}{5}\times {84}=33.6$ moles of acetylene $C_2H_2$

Thus Oxygen is the limiting reagent as it limits the formation of products. Acetylene is excess reagent as it is present in excess.

2 moles of acetylene $C_2H_2$ produce= 4 moles of carbon dioxide $CO_2$ .

33.6 moles of acetylene $C_2H_2$ produce= $\frac{4}{2}\times {33.6}=67.2$ moles of of carbon dioxide $CO_2$ .

8 0

3 years ago

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14. The following are a list of the four parts of John Dalton's atomic theory Indicate which of

Damm [24]

Answer:

1

all matter is made of tiny particles called atom

5 0

3 years ago