Answer:
149.79
Explanation:
Formula
Joules = m * c * delta (t)
Givens
J = 28242
m = ?
c = 4.19
Δt = 63 - 18 = 45
Solution
28242 = m * 4.19 * 45
28242 = m * 188.55
m = 28242 / 188.55
m = 149.79
Oxygen has an atomic number of eight. When two oxygen atoms come together, they form a(n) covalent (double) bond.
This problem may easily solved by applying the conservation of mass, which states that the total mass before and after a change is constant because mass can neither be created nor destroyed.
We know that water consists of only hydrogen and water, and that there are no other reactants except hydrogen and oxygen. Thus:
Mass of reactants = Mass of product
mass of hydrogen + mass of oxygen = mass of water
4 + mass of oxygen = 36
mass of oxygen = 32 grams
Answer:
Zero with the subscripts, +2 without them.
Explanation:
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In this case, since we consider that two silicon are bonded with four oxygen atoms to form silicon oxide according to the following chemical equation:
It is also possible to realize it can be simplified to obtain:
Which means that the total charge with the subscripts is zero, and without the subscripts +2 (+4-2).
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Answer:
Approximately 1.9 kilograms of this rock.
Explanation:
Relative atomic mass data from a modern periodic table:
To answer this question, start by finding the mass of Pb in each kilogram of this rock.
89% of the rock is . There will be 890 grams of in one kilogram of this rock.
Formula mass of :
.
How many moles of formula units in that 890 grams of ?
.
There's one mole of in each mole of . There are thus of in one kilogram of this rock.
What will be the mass of that of ?
.
In other words, the in 1 kilogram of this rock contains of lead .
How many kilograms of the rock will contain enough to provide 1.5 kilogram of ?
.