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Alekssandra [29.7K]
3 years ago
12

Water covers over 70% of planet Earth and most of the water is salt water. Which

Chemistry
1 answer:
Serga [27]3 years ago
6 0

Answer:

D. 4

Explanation:

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How many chlorine molecules are in 35.5g of chlorine gas
Karo-lina-s [1.5K]
Since chlorine is one of the 7 diatomic elements we know that chlorine appears as Cl₂ gas naturally.  That means that the molar mass of a chlorine gas is 70.9g/mol.  That being said, first you need to find the number of moles of chlorine gas that are present in a 35.5g sample.  To do this divide 35.5g by the molar mass of chlorine gas (70.9g/mol) to get 0.501mol of chlorine.  Then you have to multiply 0.501mol by 6.02×10²³ to get the number of chlorine gas molecules.  Therefore 3.01×10²³ molecules of chlorine gas are present in a 35.5g sample.

I hope that helps.  Let me know in the comments if anything is unclear.
7 0
4 years ago
What percentage of the mass of a carbon-12 atom is
Lynna [10]

Answer:

% of mass of electrons in C = 0.0272

Explanation:

Atomic no. of carbon = 6

So, no. of electron = 6

Mass of an electron = \frac{1}{1836} amu

Mass of 6 electrons = 6 \times \frac{1}{1836} = 0.003268 amu

Mass of C = 12.0107 u

% of mass of electrons in C = \frac{Mass\ of\ all\ electrons}{Mass\ of\ C}\times 100

% of mass of electrons in C = \frac{0.003268}{12.0107}\times 100=0.0272 \%

7 0
3 years ago
Once the torch is lit why must the acetylene flow be increased until the flame stops smoking
mojhsa [17]
Once the torch is lit, the acetylene flow must be increased until the flame stops smoking <span>before the oxygen is turned on for adjustment in order to keep the tip of the torch cool.

You should also note that while lighting the torch, you should keep the spark lighter near the tip but not covering it.</span>
5 0
3 years ago
A gas mixture at 535.0°C and 109 kPa absolute enters a heat exchanger at a rate of 67.0 m3/hr. The gas leaves the heat exchanger
SVEN [57.7K]

Answer:

the heat rate required to cool down the gas from 535°C until 215°C is -2.5 kW.

Explanation:

assuming ideal gas behaviour:

PV=nRT

therefore

P= 109 Kpa= 1.07575 atm

V= 67 m3/hr = 18.6111 L/s

T= 215 °C = 488 K

R = 0.082 atm L /mol K

n = PV/RT = 109 Kpa = 1.07575 atm * 18.611 L/s /(0.082 atm L/mol K * 488 K)

n= 0.5 mol/s

since the changes in kinetic and potencial energy are negligible, the heat required is equal to the enthalpy change of the gas:

Q= n* Δh = 0.5 mol/s * (- 5 kJ/mol) =2.5 kW

7 0
3 years ago
How do you solve the level of a liquid in a graduated cylinder
Nezavi [6.7K]
Don’t really understand what you’re asking but, if you’re asking how to read a graduated cylinder:

Look at the graduated cylinder at eye level, find the meniscus, whatever the meniscus is at is your answer.
8 0
3 years ago
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