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3 years ago

A chemist mixes sodium with water and witnesses a violent reaction between the metal and water. this is best classified as

1 answer:

8 0

A law is statement about an observed concept. A theory involves the explanation of scientific concepts or principles. A hypothesis is the predicted explanation about some concepts that has to be tested in order to prove it to be right. An observation is the observing the results of a scientific experiment carried out to test an hypothesis.

Here the given statement 'A chemist mixes sodium with water and witnesses a violent reaction between the metal and water,' can be classified as an observation as it explains what the chemists observes as a result of his chemical experiment or test..

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Which is the product of cellular respiration?

Liono4ka [1.6K]

Answer:

I'm pretty sure the answer is ATP

Explanation:

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3 years ago

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A glass cylinder contains 2 gases at a pressure of 106 kPa. If one gas is at 7 kPa, what is the pressure of attributed to the ot

Ivan

Answer:

b) 99 kPa

Explanation:

According to Daltons law of partial pressure, the total pressure of a mixture of two or more non reactive gases is the sum of their individual pressures. Let the total pressure of a mixture of n number of gases be $P_{total}$ and their individual pressure be $P_1,P_2,P_3,\ .\ .\ .\ ,\ P_n$ , According to Daltons partial pressure law:

$P_{total}=P_1+P_2+P_3+.\ .\ .+P_n$

Since A glass cylinder contains 2 gases at a pressure of 106 kPa, therefore n = 2. Also one gas ( $P_1$ ) is at 7 kPa. Using Daltons partial pressure law:

$P_{total}=P_1+P_2+P_3+.\ .\ .+P_n\\P_{total}=P_1+P_2\\106\ kPa=7\ kPa+P_2\\P_2=106\ kPa-7\ kPa\\P_2=99\ kPa$

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3 years ago

How many atoms are there in 0.32g of copper

aivan3 [116]

The number of atoms that are in 0.32 g of copper are

3.01 x10^21 atoms

calculation

Step 1: find the number of moles of Copper

moles = mass/molar mass

= 0.32 g /63.5 g/mol=0.005 moles

Step 2: use the Avogadro's constant to determine the number of atom

in 0.005 moles of Cu

that is according to Avogadro's law 1 mole =6.02 x10^23 atoms

0.005 moles=? atoms

by cross multiplication

= (0.005 moles x 6.02 x10^23 atoms) / 1 mole= 3.01 x10 ^21 atoms

7 0

3 years ago

Air at 30.0% relative humidity is cooled isobarically at 1 atm absolute from 75.0°C to 35.0°C. a. Estimate the dew point and the

Dvinal [7]

Answer:

a. Dew point: 48.7°C. Degrees of superheat 26.3°C

b. $3.33mol/m^3$

c. $P=3.34atm$

Explanation:

a. Based on the psychometric chart of air, the specific volume of air at the given conditions is:

$v =\frac{RT}{PM} =\frac{0.082\frac{atm*L}{mol*K}*348.15K}{1atm*28.97g/mol} *\frac{1m^3}{1000L}*\frac{1000g}{1kg} =0.98544m^3/kg$

The dew point at the specific volume and the 30%-humidity has a value of 48.7°C, it means that there are 75°C-48.7°C=26.3°C of superheat.

b. At 75°C the molar fraction of water is 11580Pa/101625Pa=0.114 moles per cubic meter of feed gas are:

$\frac{n}{V}=y_{H_2O}\frac{P}{RT}=0.114\frac{1atm}{0.082\frac{atm*L}{mol*K}*348.15K} }*\frac{1000L}{1m^3} \\\frac{n}{V}=4mol/m^3$

Once the 35°C are reached, the mole fraction of water is 1688Pa/101325Pa=0.017 and remaining moles per cubic meter of feed gas are:

$\frac{n}{V}=y_{H_2O}\frac{P}{RT}=0.017\frac{1atm}{0.082\frac{atm*L}{mol*K}*308.15K} }*\frac{1000L}{1m^3} \\\frac{n}{V}=0.673mol/m^3$

So the condensed moles per cubic meter of feed gas are:

$4mol/m^3-0.673mol/m^3=3.33mol/m^3$

c. Considering the Raoult's law, one computes the pressure as follows:

$P=\frac{P^{sat}_{H_2O}}{y_{H_2O}}$

At 75°C and 30%-humidity, the saturation water vapor pressure has a value of 38599Pa, thus:

$P=\frac{38599Pa}{0.114}*\frac{1atm}{101325Pa} \\P=3.34atm$

Best regards.

6 0

3 years ago

Answers this...i gave brainlest!!

Elanso [62]

6- B
7- B
8- D
9- A
10- C
11-B
12- D

have a wonderful day!!! also i need that brainliest!!!

3 0

3 years ago

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