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3 years ago

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Chemistry

1 answer:

fomenos3 years ago

8 0

Answer:

Q1: c. 7.2 g.

Q2: a. 0.42 M.

Explanation:

Hello there!

In this case, according to the definition of molarity as moles of solute divided by volume of solution in liters, we can proceed as follows:

Q1: Here, given the molarity and volume we can calculate the moles of the sugar as follows:

$n=M*V=0.4mol/L*0.1L\\\\n=0.04 mol$

Next, since its molar mass is about 180 g/mol, the mass turns out:

$0.04mol*\frac{180g}{1mol} =7.2 g$

Therefore, the answer is c. 7.2 g.

Q2: Here, recalling the definition of molarity, we can just plug in the 0.629 moles and 1.500 L to obtain:

$M=\frac{0.629mol}{1.5L}\\\\M=0.42M$

Therefore, the answer is a. 0.42 M.

Best regards!

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What mass of water is produced by the combustion 1.2 x 10 exp 26 molecules of butane

algol [13]

Answer:

17.94 kg of water

Explanation:

The combustion reaction of balanced butane (C₄H₁₀) is as follows:

2 C₄H₁₀ + 13 O₂ ⇒ 8 CO₂ + 10 H₂O

The amount of butane molecules can be transferred to moles to establish the stoichiometric relationship with water and calculate the moles of water that are formed:

6.02x10²³ molecules _____ 1 mol of butane

1.2x10²⁶ molecules _____ X = 199.34 moles of butane

Calculation: 1.2x10²⁶ molecules x 1 mol / 6.02x10²³ molecules = 199.34 moles of butane

According to the balanced equation:

2 moles butane _____ 10 moles of water

199.34 moles of butane _____ X = 996.68 moles of water

Calculation: 199.34 moles x 10 moles / 2 moles = 996.68 moles of water

And now, you can calculate the mass of the amount of moles obtained from water:

1 mole of water _____ 18 g

996.68 moles of water _____ X = 17.94 kg of water

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Therefore, the combustion of 1.2x10²⁶ butane molecules produces 17.94 kg of water.

4 0

4 years ago

Show

SIZIF [17.4K]

Answer: 0.9375 g

Explanation:

To calculate the number of moles for given molarity, we use the equation:

$\text{Moles of solute}={\text{Molarity of the solution}}\times{\text{Volume of solution (in L)}}$ .....(1)

Molarity of $HCl$ solution = 0.75 M

Volume of $HCl$ solution = 25.0 mL = 0.025 L

Putting values in equation 1, we get:

$\text{Moles of} HCl={0.75}\times{0.025}=0.01875moles$

$CaCO_3(s)+2HCl(aq)\rightarrow CaCl_2(s)+CO_2(g)+H_2O(l)$

According to stoichiometry :

2 moles of $HCl$ require = 1 mole of $CaCO_3$

Thus 0.01875 moles of $HCl$ will require= $\frac{1}{2}\times 0.01875=0.009375moles$ of $CaCO_3$

Mass of $CaCO_3=moles\times {\text {Molar mass}}=0.009375moles\times 100g/mol=0.9375g$

Thus 0.9375 g of $CaCO_3$ is required to react with 25.0 ml of 0.75 M HCl

6 0

3 years ago

Determine the frequency of radiation whose wavelength is 7.67 x 10^-7 cm. Then, determine the amount of energy in the radiation.

dimulka [17.4K]

Answer:

They frequency = 3.9 * 10^16 Hz

The amount of energy E = 2.58 *10^-17 J

Explanation:

Step 1: Data given

wavelength is 7.67 * 10^-7 cm

Step 2: Calculate the frequency

f = c / λ

⇒ with λ = the wavelength in nm = 7.67 nm

⇒ with c = the speed of light = 3.00 * 10^8 m/s

⇒ f = the frequency = TO BE DETERMINED

f = (3.00 * 10^8 m/s) / 7.67 * 10^-9 m

f = 3.9 * 10 ^16 /s = 3.9 * 10^16 Hz

They frequency is 3.9 * 10^16 Hz

Step 3: Calculate the amount of energy

E = h *f

⇒ with E = the amount of energy (in joule)

⇒ h = Planck's constant = 6.626 *10^-34 J*s

⇒ with f = the frequency

E = 6.626 *10^-34 J*s * 3.9 * 10^16 Hz

E = 2.58 *10^-17 J

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3 years ago

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Hellppppppp asap please NO FILES ​

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