Answer:
When the weather is nice, many people begin to work on their yards and homes. For many projects, sand is needed as a foundation for a walk or to add to other materials. You could order up twenty million grains of sand and have people really stare at you. You could order by the pound, but that takes a lot of time weighing out. The best bet is to order by the yard, meaning a cubic yard. The loader can easily scoop up what you need and put it directly in your truck.
Avogadro’s Number
It certainly is easy to count bananas or to count elephants (as long as you stay out of their way). However, you would be counting grains of sugar from your sugar canister for a long, long time. Atoms and molecules are extremely small – far, far smaller than grains of sugar. Counting atoms or molecules is not only unwise, it is absolutely impossible. One drop of water contains about 10 22 molecules of water. If you counted 10 molecules every second for 50 years without stopping you would have counted only 1.6 × 10 10 molecules. Put another way, at that counting rate, it would take you over 30 trillion years to count the water molecules in one tiny drop.
Explanation:
Calculate first the number of moles of ethylene glycol by dividing the mass by the molar mass.
n = (6.21 g ethylene glycol) / 62.1 g/mol
n = 0.1 mol
Then, calculate the molality by dividing the number of moles by the mass of water (in kg).
m = 0.1 mol/ (0.025 kg) = 4m
Then, use the equation,
Tb,f = Tb,i + (kb)(m)
Substituting the known values,
Tb,f = 100°C + (0.512°C.kg/mol)(4 mol/kg)
<em>Tb,f = 102.048°C</em>
Missing question:
Nitrogen: <span>2.0 L; </span>1.0 atm; 25°<span>C.
Oxygen: 3</span>.0 L; 2.0 atm; 25°C.
<span>When the valve between the two containers is opened, nitrogen gas moves from one container to another container and gases are mixed together, total volume of nitrogen is than:
V(nitrogen) = 2,0 L + 3,0 L = 5,0 L.</span>
<span>Let's assume
that the oxygen gas has ideal gas behavior.
Then we can use ideal gas formula,
PV = nRT</span>
Where, P is the pressure of the gas (Pa), V is the volume of the gas
(m³), n is the number of moles of gas (mol), R is the universal gas
constant ( 8.314 J mol⁻¹ K⁻¹) and T is temperature in Kelvin.
<span>
P = 2.2 atm = 222915 Pa
V = 21 L = 21 x 10</span>⁻³ m³
n = ?
R = 8.314 J mol⁻¹ K⁻¹
<span>
T = 87 °C = 360 K
By substitution,
</span>222915 Pa x 21 x 10⁻³ m³ = n x 8.314 J mol⁻¹ K⁻<span>¹ x 360 K
n
= 1.56</span><span> mol</span>
<span>
Hence, 1.56 moles of the oxygen gas are </span><span>
left for you to breath.</span><span>
</span>
The objects mass I took physical science
