Depends on the grade of the test. But for the most part if it’s below a 78, it’ll drop, If it’s above it’ll raise. It shouldn’t drop or raise it more than 3 point/percent.
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Answer:</h3>
250.756 moles He
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Explanation:</h3>
From the question we are given;
Volume, L = 685 L
Temperature, T = 621 K
Pressure, P = 189 × 10 kPa
We are required to calculate the number of moles of the gas,
Using the Ideal gas equation,
PV = nRT, where P is the pressure, V is the volume, T is the temperature, n is the number of moles, and R is the ideal gas constant.
We can replace the known variables and constant in the equation to get the unknown variable, n.
Using ideal gas constant as 8.3145 L.kPa/K/mol



n = 250.756 moles
The moles of helium contained in the sphere is 250.756 moles
Answer:
The density of igneous rocks is related to its color. Darker colored rocks have a higher density because of its greater mineral and iron content. Its characteristics is opposite compared to lighter colored rocks that have less density because of lower mineral and iron content
In chemistry:
When something is oxidized, it loses electrons.
When something is reduced, it gains electrons.
So the correct statements would be the second to last and third to last statements
Answer:
No
Explanation:
The mass fraction is defined as:

where:
- wi: mass fraction of the substance i
- mi: mass of the substance i
- mt: total mass of the system
<u><em>The mass fraction of two substances (A and B), will be the same, ONLY if the mass of the substance A (mA) is the same as the mass of the substance B (mB).</em></u>
An equimolar mixutre of O2 and N2 has the same amount of moles of oxygen and nitrogen, just to give an example let's say that the system has 1 mole of O2 and 1 mole of N2. Then using the molecuar weigth of each of them we can calculate the mass:
mA= 1 mole of O2 * 16 g/1mol = 16 g
mB=1 mole of N2 *28 g/1mol=28 g
As mA≠mB then the mass fractions are not equal, so the answear is NO.