Excess HCl is added to 234 g of Na2S solution as shown by the equation below:
Na2S(aq) + 2HCl(aq) →2NaCl(aq) + H2S(g)
How many liters of H2S gas are produced at standard temperature and pressure (STP)? The molar mass of Na2S is 78 g.

Answer:

False

Explanation:

Roman numerals are seen in the names of several compounds. They often appear immediately after the name of central atom in the molecule.

These Roman numerals are used to depict the oxidation state of the central atom in the molecule and not to show how many of that ion appear in the formula.

For instance, in carbon IV oxide, the Roman numeral IV shows that the central atom in the compound-carbon is in the +4 oxidation state.

Answer:

The most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Explanation:

The mass, in percentage, of eah isotope of Calcium is their fractional composition multiplied by 100:

40Ca-0.96941*100 =  96.941% of ⁴⁰Ca

42Ca-0.00647*100 = 0.647% of ⁴²Ca

43Ca-0.0013*100 = 0.13% of ⁴³Ca

44Ca-0.02086*100 = 2.086% ⁴⁴Ca

46Ca-0.00004*100 = 0.004% ⁴⁶Ca

48Ca-0.00187*100 = 0.187% of ⁴⁸Ca

That means the most abundant isotope is ⁴⁰Ca and the least abundant is ⁴⁶Ca

Answer:

The maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic acid from 15 mL of water = 94.9%

Note: The question is incomplete. A similar but complete question is given below:

The solubility of benzoic acid in water is 6.80g per 100mL at 100 degrees C and 0.34 g per 100mL at 25 degrees C.

Calculate the maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic acid from 15 mL of water, assuming the solution is filtered at 25 degrees C.

Explanation:

Solubility of benzoic acid in water at 100 degrees C = 6.80g per 100mL

Solubility of benzoic acid in water  at 25 degrees C =  0.34 g per 100mL

Mass of benzoic acid to be theoretically recovered from 100 mL of water = 6.80 g - 0.34 g = 6.46 g

At 25 degrees;

0.34 g of benzoic acid is present in 100 mL of water

x g of  benzoic acid will be present in 15 mL of water

x = 0.34 × 15 / 100 = 0.051 g

Mass of benzoic acid to be theoretically recovered from 25 mL of water = 1.00 g - 0.051 g = 0.949 g

Maximum theoretical percent recovery = (mass recovered / original mass dissolved) x 100%

Maximum theoretical percent recovery =  (0.949 / 1.00) × 100% = 94.9 %

Therefore, the maximum theoretical percent recovery from the recrystallization of 1.00 g of benzoic acid from 15 mL of water = 94.9%

Answer:

21g

Explanation:

no.ofmol fe2o3=39.5/(56×2+16×3)=0.25mol

from equation 1mole fe2o3 react with 3mole co

so,0.25mol fe2o3 react with 0.75mol co

mass of co=0.75×(12+16)=21g

Answer:

Approximately [tex]20.8\; \rm g[/tex].

Explanation:

[tex]\rm Fe_2O_3 \, (s) + 3\; CO\, (g) \to 2\; Fe\, (s) + 3\; CO_2\, (g)[/tex].

Relative atomic mass:

Formula mass:

[tex]\begin{aligned}M({\rm Fe_2O_3}) &= 2 \times 55.845 + 3 \times 15.999\\ &= 159.687\; \rm g \cdot mol^{-1}\end{aligned}[/tex].

[tex]\begin{aligned}M({\rm CO}) &= 12.011 + 15.999\\ &= 28.010\; \rm g \cdot mol^{-1}\end{aligned}[/tex].

Number of moles of [tex]\rm Fe_2O_3[/tex] formula units in [tex]39.5\; \rm g[/tex] of this compound:

[tex]\begin{aligned}&n({\rm Fe_2O_3}) \\ &= \frac{m({\rm Fe_2O_3})}{M({\rm Fe_2O_3})} \\ &= \frac{39.5\; \rm g}{159.687\; \rm g \cdot mol^{-1}}\approx 0.247\; \rm mol\end{aligned}[/tex].

Refer to the balanced equation for this reaction.

Hence, for every formula unit of [tex]\rm Fe_2O_3[/tex] that this reaction consumes, [tex]3\; \rm mol[/tex] of [tex]\rm CO[/tex] molecules would also need to be consumed. Therefore, if neither reactant is in excess:

[tex]\displaystyle \frac{n({\rm CO})}{n({\rm Fe_2O_3})} = \frac{3}{1} = 3[/tex].

Calculate the number of moles of [tex]\rm CO[/tex] required to react with that [tex]39.5\; \rm g[/tex] of [tex]\rm Fe_2O_3[/tex]:

[tex]\begin{aligned}&n({\rm CO}) \\ &= n({\rm Fe_2O_3}) \cdot \frac{n({\rm CO})}{n({\rm Fe_2O_3})} \\[0.5em] &\approx 0.247\; \rm mol \times 3 \approx 0.742\; \rm mol\end{aligned}[/tex].

Make use of the formula mass of [tex]\!\rm CO[/tex] to find the mass of that [tex]0.742\; \rm mol[/tex] of [tex]\rm CO[/tex] molecules:

[tex]\begin{aligned} m({\rm CO}) &= n({\rm CO}) \cdot M({\rm CO}) \\ &\approx 0.742\; \rm mol \times 28.010\; \rm g \cdot mol^{-1} \\ &\approx 20.8\; \rm g\end{aligned}[/tex].

Explanation:

this explanation may help u to understand:)

Answer:

yes

Explanation:

cos of high electron transfer

Answer: 26 moles of [tex]PH_3[/tex] are required for the reaction.

Explanation:

We are given:

Moles of [tex]P_4O_{10}[/tex] = 6.5 moles

The given chemical reaction follows:

[tex]4PH_3(g)+8O_2(g)\rightarrow P_4O_{10}(s)+6H_2O(g)[/tex]

By the stoichiometry of the reaction:

If 1 mole of [tex]P_4O_{10}[/tex] is produced by 4 moles of [tex]PH_3[/tex]

So, 6.5 moles of [tex]P_4O_{10}[/tex] will be produced by = [tex]\frac{4}{1}\times 6.5=26mol[/tex] of [tex]PH_3[/tex]

Hence, 26 moles of [tex]PH_3[/tex] are required for the reaction.

Answer:

0.348 L

Explanation:

Step 1: Given data

Step 2: Calculate the volume of the concentrated solution

We want to prepare a dilute solution from a concentrated one. We can calculate the volume of the concentrated solution using the dilution rule.

C₁ × V₁ = C₂ × V₂

V₁ = C₂ × V₂ / C₁

V₁ = 1.07 M × 2.11 L / 6.49 M = 0.348 L

Answer: c potassium.

Explanation:

potassium is the most reactive metal among the given options.

D is absolutely wrong.

Answer:

Laws governing gas behavior.

Explanation:

Boyle's law:

It relates the pressure and volume of an ideal gas at a constant temperature.

According to this law:

"The volume of a fixed amount of gas at constant temperature is inversely proportional to its pressure".

[tex]P \alpha V[/tex].

Charle's law:

It relates the volume and absolute temperature of an ideal gas at a constant pressure.

According to this law:

"The volume of a fixed amount of gas at constant pressure is directly proportional to its absolute temperature".

[tex]V \alpha T[/tex].

Avogadro's law:

According to this law:

equal volumes of all gases under the same conditions of temperature and pressure contain, an equal number of moles.

[tex]V \alpha n[/tex].

Ideal gas equation:

By combining all the above-stated gas laws, this equation is formed as shown below:

[tex]V \alpha \frac{nT}{P} \\=> V= R. nT/ P\\=>PV=nRT[/tex]

R is called universal gas constant.

It has a value of 0.0821L.atm.mol-1.K-1.

Answer:

Boyle's law, Charle's law,  Guy Lussac's law and Avogadro's law

Explanation:

All the gases behaves similarly when the environment conditions are normal. But when the physical condition changes like when the pressure, volume or temperature changes, the gas behaves differently and shows a deviation.

The number of gas laws are :

Boyle's Law

Boyle's law states that when the temperature remaining constant, the pressure of the gas varies inversely to the volume of the gas.

i.e.   [tex]P \propto \frac{1}{V}[/tex]

Charle' law

Charle's law states that when pressure is constant, the temperature of a gas is directly proportional to the volume.

i.e. , [tex]$T \propto V$[/tex]

Gay Lussac's law

Gay - Lussa law states the volume and the mass of the pressure of the gas is directly proportional to the  temperature of the gas.

i.e. P.T = constant

Avogadro's law

It states that under the conditions of same pressure as well as temperatures, the gases having equal volumes will have same numbers of molecules.

i.e. [tex]\frac{V_1}{n_1}=\frac{V_2}{n_2}[/tex] = constant

Answer: As temperature increases, the number of collisions increases and the energy of the collisions increases.

Explanation:

According to collision theory, for a reaction to take place it is necessary to have collisions between the reacting species or atoms.

A collision will only be effective if species coming together have a certain minimum value of internal energy equal to the activation energy of the reaction.

More is the number of collisions taking place in a chemical reaction more will be the kinetic energy of its molecules. As kinetic energy is the energy acquired due to motion of atoms or a substance.

Also, collisions increases with increase in temperature as:

[tex]K.E = \frac{3}{2}kT[/tex]

Kinetic energy is directly proportional to temperature. So, more is the temperature more will be energy of molecules.

Thus, we can conclude that as temperature increases, the number of collisions increases and the energy of the collisions increases.

Answer: 88 grams

Explanation:

Answer:

D. the minerals they contain

Hope this answer is right!!

Answer:

turtle

Explanation:

they are slow and they take there time

Four quantities must be known for a complete physical description of a sample of a gas: temperature, volume, amount, and pressure. ... The height of the mercury column is proportional to barometric pressure, which is often reported in units of millimeters of mercury (mmHg), also called torr.

Answer:

The answer is C... I am almost positive.

Answer: The volume of given amount of ethanol at this temperature is 159.44 mL

Explanation:

Specific gravity is given by the formula:

[tex]\text{Specific gravity}=\frac{\text{Density of a substance}}{\text{Density of water}}[/tex]

We are given:

Density of water = 0.997 g/mL

Specific gravity of ethanol = 0.787

Putting values in above equation, we get:

[tex]0.787=\frac{\text{Density of a substance}}{0.997g/mL}\\\\\text{Density of a substance}=(0.787\times 0.997g/mL)=0.784g/mL[/tex]

Density is defined as the ratio of mass and volume of a substance.

[tex]\text{Density}=\frac{\text{Mass}}{\text{Volume}} [/tex] ......(1)

Given values:

Mass of ethanol = 125 g

Density of ethanol = 0.784 g/mL

Putting values in equation 1, we get:

[tex]\text{Volume of ethanol}=\frac{125g}{0.784g/mL}=159.44mL[/tex]

Hence, the volume of given amount of ethanol at this temperature is 159.44 mL

Answer:

1.104 J/g°C

Explanation:

Using Q = m × c × ∆T

Where;

m = mass of substance (g)

c = specific hear capacity (J/g°C)

∆T = change in temperature (°C)

For a colorimeter,

Q(water) = - Q(metal)

m. c. ∆T (water) = - m. c. ∆T (metal)

According to the information provided;

For water:

m = 28.0g

c = 4.184 J/g°C

∆T = (21.23 - 19.73°C)

For the metal:

m = 2.05g

c = ?

∆T = (21.23 - 98.88°C)

m. c. ∆T (water) = - m. c. ∆T (metal)

[28 × 4.184 × (21.23 - 19.73°C)] = -[2.05 × c × (21.23 - 98.88°C)]

[117.152 × 1.5] = -[2.05 × c × (-77.65)]

175.728 = -[-159.1825c]

175.728 = 159.1825c

c = 175.728 ÷ 159.1825

c = 1.104

c = 1.104 J/g°C

Answer: See explanation

Explanation:

Vacuum filtration is referred to as a fast filtration technique that is used in the separation of solids from liquids. It is also used to collect a desired solid. It basically uses a side-arm flask and a Buchner funnel.

Based on the question, the techniques that should be used to ensure a quantitative separation goes thus:

• Wet the filter paper before the mixture is poured into the filter funnel.

• Then, carefully rinse the flask with a little amount of water into the filter funnel.

• After that, the solid on the filter paper should be washed the with a small amount of water.

• Finally, Dry the solid on the filter paper when the separation is done.

Answer:

Sound travels through the air in approximately 332 metres per second?

Explanation:

is this what you are looking for>

Answer:

[tex]v_{solute}=160mL[/tex]

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to calculate the volume of methyl alcohol solute by using the definition of by-volume percentage:

[tex]\%v=\frac{v_{solute}}{v_{solution}} *100\%[/tex]

Whereas we solve for the volume of the solute as shown below:

[tex]v_{solute}=\frac{\%v*v_{solution}}{100\%} \\\\v_{solute}=\frac{80\%*200mL}{100\%}\\\\ v_{solute}=160mL[/tex]

Regards!

Answer:

Lake Treatment

Explanation:

Sulphuric dioxide produced by industries and released into the atmosphere returns as acid rain or sulphuric acid. In lakes impacted by acid rain, such as in Ontario, Canada, the application of alkalis dropped by airplanes can control and neutralize the water's pH level.

Answer:

SI

Explanation:

I would say silicon because it is also another metalloid. Boron is a metalloid.

Answer:

Option 1. NO

Explanation:

The balanced equation for the reaction is given below below:

4NH₃ + 6NO —> 5N₂ + 6H₂O

From the balanced equation above,

4 moles of NH₃ reacted with 6 moles of NO.

Finally, we shall determine the limiting reactant. This can be obtained as follow:

From the balanced equation above,

4 moles of NH₃ reacted with 6 moles of NO.

Therefore, 1.24 moles of NH₃ will react with = (1.24 × 6)/4 = 1.86 moles of NO

From the calculation made above, we can see that a higher amount of NO (i.e 1.86 moles) than what was given (i.e 1.79 moles) is needed to react completely with 1.24 moles of NH₃.

Therefore, NO is the limiting reactant and NH₃ is the excess reactant.

Thus, the 1st option gives the correct answer to the question

Answer:

1. NO .

Explanation:

Hello there!

In this case, according to the given information, it turns out possible for us to identify the limiting reactant by simply calculating the moles of any product, say N2, via the moles of each reactant and including the corresponding mole ratio (4:5 and 6:5):

[tex]1.24molNH_3*\frac{5molN_2}{4molNH_3}=1.55molN_2 \\\\1.79molNO*\frac{5molN_2}{6molNO}=1.50molN_2[/tex]

Thus, since NO yields the fewest moles of N2 product, we infer it is the limiting reactant.

Regards!

Answer:

Chlorine gas reacts with potassium bromide to form potassium chloride in solution and liquid bromine.

Answer:

DDDDD

Explanation:

Answer:

?

Explanation:

Answer:

density = d = 19.3g/cm^3

Mass of gold = m= 20g

now

we know,

density = mass / volume

or volume = mass/ density

volume = 20/19.3 = 1.036cm^3

Explanation:

Answer:

A).

Strontium Sulphate is soluble

Answer:

option b is your right answer