2. List three types of chemical changes. Help me

Which countries were the world leaders in space exploration throughout the 1960's?

g100num [7]

Answer:

the us and the soviet union

Explanation:

7 0

3 years ago

Which of the following is the correct equation for the reaction below?

fenix001 [56]

Answer:

Option C.

2 Mg (s) + O₂(g) → 2MgO (s)

Explanation:

Two moles of magnesium solid react with one mol of oxygen gas to

form two moles of magnesium-oxide solid

2 Mg (s) + O₂(g) → 2MgO (s)

That's the reaction for the magnessium oxide's formation.

Be careful cause we do not say molecules, they are moles.

The stoichiometry indicates the number of moles that react and the moles which are produced.

It is a redox reaction, because the magnessium is oxidized and the oxygen is reduced. Both elements, changed the oxidation states.

4 0

3 years ago

Read 2 more answers

How many significant figures are in the mass 3.0047 g?

Rudik [331]

Answer:

5 significant figures

5 0

4 years ago

You have a red ballooe that has a volume of 20 liters, a pressure of 1.5 atmospheres and a temperature of 28 C. What is the volu

ki77a [65]

Explanation:

The given data is as follows.

$P_{1}$ = 1.5 atm, $V_{1}$ = 20 L, $T_{1}$ = (28 + 273) K = 301 K

$P_{2}$ = 5 atm, $V_{2}$ = ?, $T_{2}$ = (50 + 273) K = 323 K

Formula to calculate the volume will be as follows.

$\frac{P_{1} \times V_{1}}{T_{1}}$ = $\frac{P_{2} \times V_{2}}{T_{2}}$

Putting the given values into the above formula as follows.

$\frac{P_{1} \times V_{1}}{T_{1}}$ = $\frac{P_{2} \times V_{2}}{T_{2}}$

$\frac{1.5 atm \times 20 L}{301 K}$ = $\frac{5 atm \times V_{2}}{323 K}$

$V_{2}$ = 0.64 L

Thus, we can conclude that the change in volume of the balloon will be 0.64 L.

6 0

3 years ago

The compound dioxane, which is used as a solvent in various industrial processes is composed of C,H, and O atoms. Combustion of

Lady_Fox [76]

Answer:

The correct formula of dioxane is C₄H₈O₂.

Explanation:

Given data:

mass of dioxane= 2.23 g

mass of water = 1.802 g

mass of carbon dioxide = 4.401 g

molar mass of dioxane = 88.1 g / mol

Molecular formula of dioxane = ?

Solution:

percentage of carbon = (4.401 g/2.23 g ) × (12 /44) × 100

= (1.98 × 0.273) × 100 = 54.1

percentage of hydrogen = (1.802 g/ 2.23 g) × (2.016 /18.016) × 100

= (0.81 × 0.112) × 100 = 9.072

percentage of oxygen = 100 - (54.1 + 9.072)

= 100 - 63.172 = 36.828

Now we will determine the number of grams atoms of carbon, hydrogen and oxygen.

No. of gram atoms of carbon = 54.1 /12 = 4.51

No. of gram atoms of hydrogen = 9.072 / 1.008 = 9

No. of gram atoms of oxygen = 36.828 / 16 = 2.302

Atomic ratio:

C :H :O 4.51/ 2.302 : 9 / 2.302 : 2.302 /2.302

C :H :O 2 : 4 : 1

Molecular formula:

Molecular formula = n × (empirical formula)

n = molar mass of compound / empirical formula mass

empirical formula mass= 2 × 12 + 4 × 1.008 + 1 × 16

empirical formula mass= 24+ 4.032 +16 = 44.032

n = 88.1 / 44.032 = 2

Molecular formula = n × (empirical formula)

Molecular formula = 2 × (C₂H₄O)

Molecular formula = C₄H₈O₂

8 0

3 years ago