Answer:
Here is the ANSWER KEY, it may also has other of the questions you don't know :)
Explanation:
https://sciencewithhorne.weebly.com/uploads/5/7/3/5/57358947/unit_11_hw_key.pdf
Answer:
b. 11.90 Liters
Explanation:
- The balanced equation for the mentioned reaction is:
<em>3O₂ + 4Al → 2Al₂O₃,</em>
It is clear that 3.0 moles of O₂ react with 4.0 moles of Al to produce 2.0 Al₂O₃.
- Firstly, we need to calculate the no. of moles (n) of 36.12 g of Al₂O₃:
<em>n = mass/molar mass</em> = (44.18 g)/(101.96 g/mol) = <em>0.4333 mol.</em>
<u><em>using cross multiplication:</em></u>
3.0 mol of O₂ produces → 2.0 mol of Al₂O₃.
??? mol of O₂ produces → 0.4333 mol of Al₂O₃.
<em>∴ The no. of moles of O₂ needed to produce 36.12 grams of Al₂O₃</em> = (3.0 mol)(0.4333 mol)/(2.0 mol) = <em>0.65 mol.</em>
- Now, we can find the volume of O₂ used during the experiment:
We can use the general law of ideal gas: <em>PV = nRT.</em>
where, P is the pressure of the gas in atm (P = 1.3 atm).
V is the volume of the gas in L (V = ??? L).
n is the no. of moles of the gas in mol (n = 0.65 mol).
R is the general gas constant (R = 0.0821 L.atm/mol.K),
T is the temperature of the gas in K (T = 290 K).
<em>∴ V = nRT/P </em>= (0.65 mol)(0.0821 L.atm/mol.K)(290 K)/(1.3 atm) = <em>11.9 L.</em>
<em>So, the right choice is: b. 11.90 Liters.</em>
Answer:
The mass of glycerol that the student should weigh out depends on the volume that is needed. For example, the density of glycerol is 1.26 g/mL. Then, if 500 mL of glycerol is needed, 630 g should be weighed.
Explanation:
Density is the amount of mass per unit of volume. Density relates how many grams 1 milliliter of a substance weighs. Thus, if the density of glycerol is 1.26 g/mL means that 1.26 grams of glycerol occupy 1 mL of volume, or, in other words, 1 mL of glycerol weighs 1.26 grams.
Therefore, if 500 mL of glycerol is required to use for an experiment, 630 grams need to be weighed:
1 mL glycerol________ 1.26 g
500 mL glycerol______ x= 500mL * 1.26 g / 1 mL = 630 g
Answer:
The given reaction is type of burning of methane.
Explanation:
Chemical equation:
CH₄ + O₂ → CO₂ + H₂O
Balanced chemical equation:
CH₄ + 2O₂ → CO₂ + 2H₂O
The given reaction is the burning of methane. When oxygen react with methane it produces carbon dioxide and water.
There are equal number of atoms of carbon, oxygen and hydrogen on both side of equation thus this reaction completely follow the law of conservation of mass.
According to the law of conservation mass, mass can neither be created nor destroyed in a chemical equation.
This law was given by french chemist Antoine Lavoisier in 1789. According to this law mass of reactant and mass of product must be equal, because masses are not created or destroyed in a chemical reaction.
Answer:
You just have to take the periodic table of the elements, take the element that interests you. Then, you look at the formula of the element, at the top left you find the number of neutrons and protons and at the bottom left you find the number of protons. Then you just have to make the number from the top left minus the number from the bottom left.
Explanation:
