Answer:
The concentration of this sodiumhydroxide solutions is 0.50 M
Explanation:
Step 1: Data given
Mass of sodium hydroxide (NaOh) = 8.0 grams
Molar mass of sodium hydroxide = 40.0 g/mol
Volume water = 400 mL = 0.400 L
Step 2: Calculate moles NaOH
Moles NaOH = mass NaOH / molar mass NaOH
Moles NaOH = 8.0 grams / 40.0 g/mol
Moles NaOh = 0.20 moles
Step 3: Calculate concentration of the solution
Concentration solution = moles NaOH / volume water
Concentration solution = 0.20 moles / 0.400 L
Concentration solution = 0.50 M
The concentration of this sodiumhydroxide solutions is 0.50 M
Al
Explanation:
The limiting reactant will be Al:
4Al + 3O₂ → 2Al₂O₃
The limiting reactant is the reactant in short supply in a chemical reaction.
Given parameters:
Mass of Al = 30g Molar mass = 27g/mol
Number of moles = 
= 
Number of moles of Al = 1.111 mole
Mass of O₂ = 30g, molar mass = 32g/mol
Number of moles = 
= 0.94mol
In the reaction:
4 moles of Al reacted with 3 moles of O₂
1.11moles of Al will require 
= 0.83mole to react
But we have been given 0.94mole of O₂. This is more than required.
Therefore O₂ is in excess and Al is the limiting reactant.
Learn more:
Limiting reagents brainly.com/question/6078553
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Neptune planet has the coldest surface temperature
<u>Explanation:</u>
With temperatures falling to -218°C in Neptune’s upper atmosphere, the planet is one of the coolest in our Solar System. Neptune is the most faraway planet from the sun. Astronomers have speculated that Neptune's huge internal temperature and the transfer of heat between the core and outer layers might be the cause why Neptune isn't significantly more chill than Uranus.
Pressures in this area range between 1 and 5 bars and the temperature reaches a high of 72 K. At this temperature, states are becoming for methane to condense, and clouds of ammonia and hydrogen sulfide are thought to form. At its core, Neptune reaches temperatures of up to 7273 K which is equivalent to the surface of the sun.
C ahaha siwvushss sjdjshsgau avians
Answer:
d. 97.60 g
Explanation:
Given parameters:
Number of moles of formaldehyde = 3.25moles
Ratio:
C H O
1 2 1
Unknown:
Mass of this sample = ?
Solution:
The empirical formula of a compound is its simplest formula. It is the simplest whole number ratio of the atoms in a given substance.
The molecular formula is the actual formula of the compound.
Since the molecular and empirical formula are the same here, the formula of the compound is;
CH₂O
To find the mass of the formaldehyde, use the expression below;
Mass = number of moles x molar mass
molar mass of CH₂O = 12 + 2(1) + 16 = 30g/mol
Mass = 3.25 x 30 = 97.5g
