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Basile [38]
3 years ago
14

I need help ASAP

Chemistry
1 answer:
vova2212 [387]3 years ago
8 0

Answer:

1.4 g/cm3

Explanation:

Density = Mass/Volume

Mass = 21g

Volume = 15cm3

Density = 21/15 = 1.4

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A solution is made containing 4.6 g of sodium chloride per 250g of water.
lozanna [386]

Answer:

\large \boxed{1.81 \, \%}

Explanation:

\text{Mass percent} = \dfrac{\text{mass of solute} }{\text{mass of solution}} \times 100 \, \%

Data:

Mass of NaCl =      4.6 g

Mass of water = 250    g

Calculations:

Mass of solution = mass of NaCl + mass of water = 4.6 g + 250 g = 254.6 g.

\text{\% m/m} = \dfrac{\text{4.6 g} }{\text{254.6 g}} \times 100 \, \% = \mathbf{1.81 \, \%}\\\\\text{The percent by mass of NaCl is $\large \boxed{\mathbf{1.81 \, \%}}$}

3 0
4 years ago
What is an octahedron?
gogolik [260]

Answer:

a three-dimensional shape having eight plane faces, especially a regular solid figure with eight equal triangular faces.

Explanation:

3 0
3 years ago
Answer plsssss I’m dumb
aev [14]

Answer:

bottom middle

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Explanation:

4 0
3 years ago
The reaction of Fe₂O₃ with CO produces Fe(s) and CO₂(g). What mass of Fe₂O₃ is required to produce 5.00 kg of Fe(s) if the perce
irina [24]

Answer:

2.75g

Explanation:

Firstly, we write a balanced equation of the reaction.

Fe2O3(s)+3CO(g)-->2Fe(s)+3CO2(g).

Now, we write the formula for the percentage yield.

Percentage yield = Actual yield/theoretical yield * 100%

From the equation, we can see that we have one unknown

We convert the 5kg to g. It must be known that 5kg is 5000g as 1kg equals 1000g.

Now, we are asked to calculate the mass of the iron iii oxide required.

From the balanced equation we can see that 1 mole of iron trioxide yielded 2 moles of Fe.

Now, let’s calculate the mass required. We calculate the actual number of moles of iron produced. This is the mass of iron divided by the molar mass. The atomic mass of iron is 56 amu. The number of moles of iron produced is 5000/56 moles

Since the mole ratio is 1 to 2, the number of moles of iron trioxide thus used is 5000/56 divided by 2 which equals 5000/112 moles.

Now, we proceed to calculate the mass of iron trioxide used. The mass is equal the molar mass multiplied by the number of moles. The molar mass of iron trioxide is 2(56) + 3(16) = 112 + 48 = 160g/mol

The mass thus required to produce 5kg of iron is 5000/112 * 160 which is 3,500g or 3.5kg. We know this to be the theoretical mass, the actual mass is calculated using the formula given above.

78.5 = actual mass/3.5 * 100

Actual mass = (3.5 * 78.5) /100

= 2.75g

6 0
3 years ago
Which describes the results of the double slit experiment? Check all that apply.
Elanso [62]

Waves produced a diffraction pattern.

Results supported the wave theory of light.

8 0
3 years ago
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