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2 years ago

Is this correct? please check

Chemistry

1 answer:

Reil [10]2 years ago

4 0

Answer:

A is the correct option

Explanation:

batteries have chemical energy and will convert to electricity and when reached to bulb, it emits light as electromagnetic rays

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n an experiment, 39.26 mL of 0.1062 M NaOH solution was required to titrate 37.54 mL of \ v unknown acetic acid solution to a ph

olasank [31]

Answer:

Molarity: 0.111M

% (w/w): 0.666

Explanation:

The reaction of NaOH with acetic acid (CH₃COOH) is:

NaOH + CH₃COOH → CH₃COO⁻Na⁺ + H₂O

where 1 mole of NaOH reacts per mole of acetic acid producing 1 mole of water and 1 mole of sodium acetate.

As 39.26mL ≡ 0.03926L of 0.1062M are required to titrate the solution of acetic acid. Moles are:

0.03926L × (0.1062mol / L) = 4.169x10⁻³ moles of NaOH. As 1 mole of NaOH reacts per mole of acetic acid:

4.169x10⁻³ moles of CH₃COOH.

Molarity is defined as ratio between moles of substance and volume of solution in liters. Thus, molarity of acetic acid solution is:

4.169x10⁻³ moles of CH₃COOH / 0.03754L = 0.111M

As molar mass of acetic acid is 60g/mol, 4.169x10⁻³ moles weights:

4.169x10⁻³ moles × (60g / mol) = 0.2501 g of acetic acid

Now, assuming density of solution as 1.00g/mL, 37.54mL weights 37.54g.

Thus, percent by weight is:

0.2501g CH₃COOH / 37.54g × 100 = 0.666% (w/w)

8 0

2 years ago

The Second Law of Thermodynamics makes it difficult for scientists to explain how the original universe became ordered.

ladessa [460]

Answer:

True :)

Explanation:

8 0

2 years ago

Read 2 more answers

What do the conclusions tell about the experiment?

Blababa [14]

Answer:

Option C

Explanation:

When you perform a experiment to test your hypothesis (your educated guess on what you think will happen) you complete trials to find data that is reliable and valid so you are only getting the best possible results. After you complete the experiment you write your conclusion which is when you take the data and you say if the data supported your hypothesis, if you did guess correctly at the beginning of the experiment. Which means the answer is option C "the conclusions tell why the data support or reject the hypothesis."

Hope this helps.

3 0

2 years ago

1.What is the specific heat capacity of granite when 20 kg absorbs 237 000 J of heat energy, causing its temperature to increase

Natalka [10]

Given :

Amount = 20 kg
Heat energy absorbed = 237,000 J
Temperature change = 15 °C

Formula applied :

$\boxed {Q = mc \triangle T}$

Q = absorbed heat
m = mass
c = specific heat capacity
ΔT = temperature change

Let's solve for c !

⇒ 237,000 = 20 × c × 15

⇒ c = 237,000 ÷ 300

⇒ $\boxed {c = 790 J kg^{-1} K^{-1}}$

∴ The specific heat capacity of granite is 790 J kg⁻¹ K⁻¹.

5 0

1 year ago

An air tight freezer measures 4 mx 5 m x 2.5 m high. With the door open, it fills with 22 °C air at 1 atm pressure.

____ [38]

Answer:

(a) Density of the air = 1.204 kg/m3

(b) Pressure = 93772 Pa or 0.703 mmHg

Explanation:

(a) The density of the air at 22 deg C and 1 atm can be calculated using the Ideal Gas Law:

$\rho_{air}=\frac{P}{R*T}$

First, we change the units of P to Pa and T to deg K:

$P=1 atm * \frac{101,325Pa}{1atm}=101,325 Pa\\\\ T=22+273.15=293.15^{\circ}K$

Then we have

$\rho_{air}=\frac{P}{R*T}=\frac{101325Pa}{287.05 J/(kg*K)*293.15K} =1.204 \frac{kg}{m3}$

(b) To calculate the change in pressure, we use again the Ideal Gas law, expressed in another way:

$PV=nRT\\P/T=nR/V=constant\Rightarrow P_{1}/T_{1}=P_{2}/T_{2}\\\\P_{2}=P_{1}*\frac{T_{2}}{T_{1}}=101325Pa*\frac{7+273.15}{22+273.15}=101,325Pa*0.9254=93,772Pa\\\\P2=93,772 Pa*\frac{1mmHg}{133,322Pa}= 0.703 mmHg$

(c) To calculate the force needed to open we have to multiply the difference of pressure between the inside of the freezer and the outside and the surface of the door. We also take into account that Pa = N/m2.

$F=S_{door}*\Delta P=2m^{2} *(101325Pa - 93772Pa)=2m^{2} *7553N/m2=15106N$

7 0

3 years ago