Answer:
The correct answer is 25 mL graduated cylinder (it should be used in all the cases)
Explanation:
In order to measure 25.00 ml sample of a solution it should be used a 25 mL graduated cylinder, as it is previously and properly calibrated. The other laboratory glassware, beaker and erlenmeyer, have graduations which are approximate, so they are used when exact volumes are not needed.
ii) graduated cylinder has the least uncertainly. It is more accurate than a beaker or erlenmeyer (to within 1%)
iii) A 25 mL graduated cylinder should be used because it is the most accurate lab glassware (between those were mentioned: beaker, erlenmeyer).
Pressure varies in the atmosphere because air molecules are being pulled down towards the center of the earth-hope this helps!
Answer:
3,85 g of Fe
Explanation:
1- The first thing to do is calculate the molar mass of the Fe2O3 compound. With the help of a periodic table, the weights of the atoms are searched, and the sum is made:
Molar mass of Fe2O3 = (2 x mass of Fe) + (3 x mass of O) = 2 x 55.88 g + 3 x 15.99 g = 159.65 g / mol
Then, one mole of Fe2O3 has a mass of 159.65 grams.
2- Then, the relationship between the Fe2O3 that will react and the iron to be produced. With the previous calculation, we can say that with one mole of Fe2O3, two moles of Fe can be produced. Passing this relationship to the molar masses, it would be as follows:
1 mole of Fe2O3_____ 2 moles of Fe
159.65 g of Fe2O3_____ 111.76 g of Fe
3- Finally, the calculation of the mass that can be produced of Fe is made, starting from 5.50 g of Fe2O3
159.65 g of Fe2O3 _____ 111.76 g of Fe
5.50 g of Fe2O3 ______ X = 3.85 g of Fe
<em>Calculation: 5.50 g x 111.76 g / 159.65 g = 3.85 g
</em>
The answer is that 3.85 g of Fe can be produced when 5.50 g of Fe2O3 react
The process which has taken place is called CRYSTALLIZATION.
Generally, crystallization is the process by which solid crystals are precipitated from solution. Crystallization can also occur when a crystal melt or when a crystal get deposited directly from a gas, although these cases are rarer compare to crystals forming from solutions.
The new pressure would be = 4.46 atm
<h3>Further explanation</h3>
Given
V₁=6.7 L(at STP, 1 atm 273 K)
V₂=1.5 L
Required
The new pressure
Solution
Boyle's Law
At a constant temperature, the gas volume is inversely proportional to the pressure applied
P₂ = (P₁V₁)/V₂
P₂ = (1 atm x 6.7 L)/1.5 L
P₂ = 4.46 atm
