Answer:
It is a chemical change.
Explanation:
A tree burning down would be a chemical change because the composition of the tree is what changes, not just the physical characteristics.
Answer:
9.33
Explanation:
balanced chemical equation:
2NH₃ + 3CuO → 3Cu + N₂ + 3H₂O
14 moles of NH3
2NH₃ → 3H₂O
14 * 2/3 = 9.33
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Answer:
Explanation:
In multiplication and division problems, the answer can have no more significant figures than the number with the fewest significant figures.
My calculator gives the result:
4658 has four significant figures.
13 has two significant figures.
You must round to two significant figures.
That is, you drop all the digits to the right of the 5 — the red line in Fig. 1 below. You are rounding to the nearest ten.
To round a number to the nearest ten, you look at the number in the ones place (1). See Fig. 2.
If the number to be dropped — the digit in the ones place — is less than 5, you drop the digit in the ones place (Fig. 3). It becomes a zero.
The number in the tens place is a trailing zero. It is not significant.
Answer : The mass of lead in 139 g of is, 86.9 grams.
Explanation : Given,
Mass of = 139 g
Molar mass of = 331.2 g/mol
Molar mass of Pb = 207.2 g/mol
Now we have to calculate the mass of lead.
As, 331.2 g of has 207.2 g of lead
So, 139 g of has of lead
Thus, the mass of lead in 139 g of is, 86.9 grams.