4Al(s)+3O2(g)__> 2Al2O3(s)

A pycnometer is a precisely weighted vessel that is used for highly accurate density determinations. Suppose that a pycnometer h

dexar [7]

Answer:

5.758 is the density of the metal ingot in grams per cubic centimeter.

Explanation:

1) Mass of pycnometer = M = 27.60 g

Mass of pycnometer with water ,m= 45.65 g

Density of water at 20 °C = d = $998.2 kg/m^3$

1 kg = 1000 g

$1 m^3=10^6 cm^3$

$998.2 kg/m^3=\frac{998.2 \times 1000 g}{10^6 cm^3}=0.9982 g/cm^3$

Mass of water ,m'= m - M = 45.65 g - 27.60 g =18.05 g

Volume of pycnometer = Volume of water present in it = V

$Density=\frac{Mass}{Volume}$

$V=\frac{m'}{d}=\frac{18.05 g}{0.9982 g/cm^3}=18.08 cm^3$

2) Mass of metal , water and pycnometer = 56.83 g

Mass of metal,M' = 9.5 g

Mass of water when metal and water are together ,m''= 56.83 g - M'- M

56.83 g - 9.5 g - 27.60 g = 19.7 g

Volume of water when metal and water are together = v

$v=\frac{m''}{d}=\frac{19.7 g}{0.9982 g/cm^3}=19.73 cm^3$

Density of metal = d'

Volume of metal = v' = $\frac{M'}{d'}$

Difference in volume will give volume of metal ingot.

v' = v - V

$v'=19.73 cm^3-18.08 cm^3=$

$v'=1.65 cm^3$

Since volume cannot be in negative .

Density of the metal =d'

= $d'=\frac{M'}{v'}=\frac{9.5 g}{1.65 cm^3}=5.758 g/cm^3$

5 0

3 years ago

Why aren't descriptive investigations repeatable?

Bad White [126]

In descriptive investigations, we still haven't formed any hypothesis yet so we seek information by asking question.

It's not repeatable because repeating the questions over and over again without any clue about what we want to seek is completely waste of time.

Hope this helps xox :)

8 0

3 years ago

Read 2 more answers

Why is Dalton credited with proposing the first atomic theory if Democritus was talking about atoms almost 2,200 years earlier?

german

Democritus *suggested* the existence of the atom, that everything was made up of tiny particles, but wasn't really able to get more specific than that. Dalton also theorized that everything was made up of indivisible particles, but went further basing his theory on actual scientific principles, such as the Law of Conservation of Mass and the Law of Constant Composition. He also said that atoms weren't created or destroyed in a chemical reaction, just rearranged. There's more to it than that, but basically, Dalton's theory was based more on science while Democritus' theory was too general to be useful in chemical situations.

4 0

3 years ago

Read 2 more answers

A student calculated the molarity of a solution prepared by dissolving 0.730 mol of table sugar (sucrose, C12H22O11) in 1.8x10^3

lara31 [8.8K]

Answer: C= 0.406 M

Explanation:

Solution.

ν

=

0.730

m

o

l

;

ν=0.730mol;

V

=

1.8

⋅

1

0

3

m

L

=

1.8

L

;

V=1.8⋅10

3 mL=1.8L;

C=0.730mol

1.8 L=0.406 M

C= 1.8L

0.730mol =0.406M

The student made a mistake because he did not convert a unit of volume from milliliters to liters. After all, molarity is defined as the number of moles of solute per liter of solution.

5 0

3 years ago

ENTER THE COEFFICIENTS DIRECTLY FROM THE BALANCED CHEMICAL EQUATION. do not reduce to lowest terms. for example: if 3 moles H2 r

dlinn [17]

Answer:

The coefficients are 2 for H₂O and 1 for Ca(OH)₂.

Explanation:

Let's consider the following reaction.

Ca(OH)₂(aq) + 2 HCl(aq) → CaCl₂(aq) + 2 H₂O(l)

According to the balanced equation, the molar ratio of H₂O to Ca(OH)₂ is 2:1. Using this conversion factor, we have the following proportion:

moles Ca(OH)₂. (2 mol H₂O ÷ 1 mol Ca(OH)₂) = moles H₂O

4 0

3 years ago