That is the element Germanium Atomic weight = 72.64
134.56 grams are 2.50 * 10^23 molecules of CaO.
Explanation:
According to Avagadro hypothesis, 1 mole of a substance contain 6.023 x 10^23 molecules or particles.
Data given:
Number of molecules of CaO =
FORMULA USED IN CALCULATION:
number of molecules = 6.02 x 10^23 x number of moles of CaO
At first number of moles is calculated:
= 2.4 moles of CaO is present
to calculate the mass of CaO in grams formula used is
mass = atomic mass x number of moles
atomic mass of CaO = 56.07 grams/mole
mass = 2.4 x 56.07
= 134.56 grams of calcium oxide is present is 2.50 * 10^23 molecules of CaO.
Octane on combustion yields CO₂ and H₂O;
2C₈H₁₈<span> + 2 5O</span>₂ → 16 CO₂<span> + 18 H</span>₂<span>O
</span>
According to equation,
2 moles Octane produces = 16 moles of CO₂
So,
498 moles Octane will produce = X moles of CO₂
Solving for X,
X = (498 mol × 16 mol) ÷ 2 mol
X = 3984 moles of CO₂
Now, Calculating for Volume,
As,
P V = n R T
Solving for V,
V = n R T / P ------- (1)
Pressure = P = 0.995 atm
<span>Volume = V = ? </span>
<span>Moles = n = 3984 </span>
<span>Gas Constant = R = 0.0821 L.atm.K</span>⁻¹.<span>mol</span>⁻¹<span> </span>
<span>Temperature = T = 23 + 273 = 296 K
</span>
Putting values in eq. 1
V = (3984 mol × 0.0821 L.atm.mol⁻¹.K⁻¹ × 296 K) ÷ 0.995 atm
Volume = 973040.95 L
Answer:
To determine the correct subscripts in a chemical formula, you have to solve how many atoms you need to balance the charge.
For example if I had the compound Calcium Fluoride I would look at the periodic table and see that Calcium's ionic formula is
Ca2+
. How do I know this? Well all elements want to have 8 valance electrons so they can be stable(happy). Seeing that Calcium has 2 valance electrons it is going to give away 2 electrons because that is easier than gaining 6 to be happy. Since Calcium has given away 2 electrons it has two more protons than electrons. We know that Protons have a Positive charge, Electrons have Negative charge, and the number of electrons is equal to the atomic number of an element in its pure non-ionic state. (Meaning it doesn't have a positive or negative charge; it is balanced.)
So if calcium gave away two electrons, it will have two more protons than an electron giving it a (2+) charge. The same process can be applied to Fluoride. Since fluoride is one to the left of the noble gases(group 18 or 8A) on the periodic table we know that it has 7 valance electrons because it is in group 7A or 17.
Knowing that we have 7 electrons the fluoride atom will gain an extra electron. Since the fluoride atom gained an extra electron it will have one more negative charge than a positive making it a ^(−)ion.
So you know that Calcium has a 2+ charge and that fluoride has a 1- charge, you then need these ions to balance out. So you need two fluorine atoms with a 1- ions to balance out the 2+ ion of calcium. Your final answer would be
CaF2
because you need two fluorine atoms to balance out the 2+ charge of the calcium.
Final Tip: Determine the charges then inverse the charges, remove the positive and negative superscipts, and write the charge numbers as a sub script. Ie. Calcium Fluoride
Ca2+ and F−
inversing and removing the charge signs would give you
Answer:
base
Explanation:
carbonic acid - H2CO3 - is a weak acid. Therefore, HCO3 itself is its conjugate base. The Na(sodium) ion is neutral.
This means that NaHCO3 is a base. (a weak one)
