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Veseljchak [2.6K]
3 years ago
13

What kind of tools did prehistoric people make with flint

Chemistry
1 answer:
barxatty [35]3 years ago
3 0
Spears and knives (Plz thank me if this helped)
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According to the reaction represented by the unbalanced equation above, how many moles of so2(g) are required to react completel
melomori [17]
2SO₂ + O₂ = 2SO₃

n(O₂)=1 mol

n(SO₂)=2n(O₂)

n(SO₂)=2 mol
6 0
3 years ago
Four nails have a total mass of 4.42 grams how many moles of iron atoms do they contain
deff fn [24]

Answer:4.42 g= 1 mol/55.845 =.079 moles of Fe

Explanation:Given 4.42 grams of Fe. The atomic weight of Fe(iron) found on the periodic table is 55.845. Divide grams by the atomic weight to convert to moles.

5 0
4 years ago
An element crystallizes in a face-centered cubic lattice. If the length of an edge of the unit cell is 0.408 nm, and the density
V125BC [204]

Answer:

Au

Explanation:

For the density of a face-centered cubic:

Density = \dfrac{4 \times M_w}{N_A \times a^3}

where

M_w = molar mass of the compound

N_A= avogadro's constant

a^3 = the volume of a unit cell

Given that:

Density (\rho) = 19.30 g/cm³

a = 0.408 nm

a = 0.408 \times 10^{-9} \times 10^{2} \ cm

a = 4.08 \times 10^ {-8} \ cm

∴

19.3 = \dfrac{4 \times M_w}{(6.023 \tmes 10^{23})\times (4.08 \times 10^{-8})^3}

M_w= \dfrac{19.3\times (6.023 \times 10^{23})\times (4.08 \times 10^{-8})^3}{4}

M_w=197.37 \ g/mol

Thus, the molar mass of 197.37 g/mol element is Gold (Au).

4 0
3 years ago
Calculate the number of grams of CO that can react with 0.400 kg of Fe2O3.
aleksandr82 [10.1K]

Answer:

mass of CO = 210.42 g

mass in three significant figures = 210. g

Explanation:

Given data:

mass of Fe2O3 = 0.400 Kg

mass of CO= ?

Solution:

chemical equation:

Fe2O3 + 3CO → 2Fe + 3CO2

Now we will calculate the molar mass of  Fe2O3 and CO.

Molar mass of  Fe2O3 = (55.845 × 2) + (16 × 3) = 159.69 g/mol

Molar mass of CO = 12+ 16 = 28 g/mol

now we will convert the kg of Fe2O3 in g.

mass of Fe2O3 = 0.400 kg × 1000 = 400 g

number of moles of Fe2O3  = 400 g/ 159.69 g/mol = 2.505 mol

mass of CO = moles of Fe2O3 × 3( molar mass of CO)

mass of CO = 2.505 mol × 84 g/mol

mass of CO = 210.42 g

mass in three significant figures = 210. g

5 0
4 years ago
Read 2 more answers
A gaseous substance turns directly into a solid. Which term describes this change?
UkoKoshka [18]

Answer:

deposition

Explanation:

Sublmation- solid transforming into a gas, skipping the liquid stage.

eveporation- a liquid transformimg into a gas

melting- a solid transforming into a liquid

deposition- the opposite of sublimation (your anwser)

7 0
3 years ago
Read 2 more answers
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