Answer:
<em>What is atmospheric pressure? -------> Atmospheric pressure is a force in an area pushed against a surface by the weight of the atmosphere of Earth, a layer of air.</em>
<em>Why does the atmosphere exert pressure? -------> Because gas particles in the air—like particles of all fluids—are constantly moving and bumping into things, so they exert pressure. </em>
<em>What is the value of atmospheric pressure at sea level, in newtons per square centimeter? -------> Atmospheric pressure at sea level is about 10 N/cm2 or 100 kPa or about 10 m of water or about 760 mm of mercury, but varies with the weather, and of course altitude.</em>
<em>I hope this helps and have a great day!</em>
Explanation:
<span>C8H10N4O2
Or do you want it in a reaction problem?
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Answer:
(a) 77.9 g/mol
(b) 3.18 g / L
Explanation:
<u>(a)</u> We need to use the ideal gas law, which states: PV = nRT, where P is the pressure, V is the volume, n is the moles, R is the gas constant, and T is the temperature in Kelvins.
Notice that we don't have moles; we instead have the mass. Remember, though that moles can be written as m/M, where m is the mass and M is the molar mass. So, we can replace n in the equation with m/M, or 21.3/M. The components we now have are:
- P: 0.880 atm
- V: 7.73 Litres
- n: m/M = 21.3 g / M
- R: 0.08206
- T: 30.00°C + 273 = 303 K
Plug these in:
PV = nRT
(0.880)(7.73) = (21.3/M)(0.08206)(303)
Solve for M:
M = 77.9 g/mol
<u>(b)</u> The equation for the molar mass is actually:
M = (dRT)/P, where d is the density
We have all the components except d, so plug them in:
77.9 = (d * 0.08206 * 298) / 1
Solve for d:
d = 3.18 g / L
Answer:
The correct answer is - C) a different number of neutrons per atom.
Explanation:
Isotopes of an element are the same element and same atomic number but with different atomic mass and physical properties. The difference in their atomic mass occurs due to isotopes of an element have a different number of neutrons per atom.
The number of protons and the numbers of electrons are the same in the isotopes but only change occurs in the numbers of the neutrons. In isotopes of uranium U-233, U-235, and U-238 have the same number of protons but a different number of neutrons per atom.
Answer:
1.09 grams
Explanation:
According to the following chemical equation:
HF + NaNO₃ -> HNO₃ + NaF
1 mol of hydrogen fluoride (HF) produces 1 mol of sodium fluoride (NaF). Thus, we first convert from mol to grams by using the molar mass (MM) of each compound:
MM(HF)= (1 g/mol x 1 H) + (19 g/mol x 1 F) = 20 g/mol HF
1 mol HF x 19.9 g/mol HF = 20 g
MM(NaF) = (23 g/mol x 1 Na) + (19 g/mol x 1 F) = 42 g/mol NaF
1 mol NaF x 42 g/mol NaF = 42 g
Thus, from 20 g of HF are produced 42 g of NaF ⇒ 20 g HF/42 g NaF. We multiply this stoichiometric ratio by the mass of NaF produced to calculate the required mass of HF:
20 g HF/42 g NaF x 2.3 g NaF = 1.09 g HF
Therefore, 1.09 grams of HF are necessary to produce 2.3 g of NaF.
