Combining oxygen gas and hydrogen gas to form liquid water is a chemical change. Pretty sure the rest are physical changes because a chemical change happens when a substance is altered completely. A physical change is when a substance keeps its components (I dunno what word to use) but just changes into a diferent shape. At least thats how my teacher explained it to me.
Answer:
2.50 atm
Explanation:
We have 10.4 g of DDT (solute), whose molar mass is 354.50 g/mol. The corresponding moles are:
10.4 g × (1 mol/354.50 g) = 0.0293 mol
The molarity of the solution is:
M = moles of solute / liters of solution
M = 0.0293 mol / 0.286 L
M = 0.102 M
We can find the osmotic pressure (π) using the following pressure.
π = M × R × T
where,
R: ideal gas constant
T: absolute temperature
π = M × R × T
π = 0.102 M × 0.0821 atm.L/mol.K × 298 K
π = 2.50 atm
Answer:
0.267 mol
Explanation:
The <em>unbalanced equation</em> for the reaction that takes place is:
Once we balance it we're left with:
- 2C₈H₁₈ + 25O₂ → 18H₂O + 16CO₂
Using the <em>stoichiometric ratio </em>of water and octane from the balanced reaction, we can <u>convert mol of water into mol of octane</u>:
- 2.40 mol H₂O *
= 0.267 mol C₈H₁₈
Thus 0.267 moles of octane are needed to produce 2.40 mol of water.
It would be a gas because gases have the highest amount of kinetic energy and takes the shape/volume of it's container.
Hope this helps(;
The empirical formula of the following compounds 0.903 g of phosphorus combined with 6.99 g of bromine.
<h3>What is empirical formula?</h3>
The simplest whole number ratio of atoms in a compound is the empirical formula of a chemical compound in chemistry. Sulfur monoxide's empirical formula, SO, and disulfur dioxide's empirical formula, S2O2, are two straightforward examples of this idea. As a result, both the sulfur and oxygen compounds sulfur monoxide and disulfur dioxide have the same empirical formula.
<h3>
How to find the empirical formula?</h3>
Convert the given masses of phosphorus and bromine into moles by multiplying the reciprocal of their molar masses. The molar masses of phosphorus and bromine are 30.97 and 79.90 g/mol, respectively.
Moles phosphorus = 0.903 g phosphorus
= 0.0293 mol
Moles bromine 6.99 g bromine
=0.0875 mol
The preliminary formula for compound is P0.0293Bro.0875. Divide all the subscripts by the subscript with the smallest value which is 0.0293. The empirical formula is P1.00Br2.99 ≈ P₁Br3 or PBr3
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