.The base which is used in space ships and submarine is

HELP !!!!!! An object moving forward at 10 m/s suddenly begins moving backward at 5 m/s. What is the most accurate explanation f

Nana76 [90]

It moves backwards 5m/s slower that forward

8 0

3 years ago

Which statement indicates that a substance may be an ionic compound?

lapo4ka [179]

If it has a metal and a nonmetal. Not sure if this helps, but I hope it does :)

3 0

3 years ago

I wanted known how many of the reaction below is energy released

Tema [17]

Answer:

2

Explanation:

In two reactions energy is released.

1) C₆H₁₂O₆ + 6O₂ → 6H₂O + 6CO₂ + heat

It is cellular respiration reaction.It involves the breakdown of glucose molecule in the presence of oxygen to yield large amount of energy. Water and carbon dioxide are also produced as a byproduct.

Glucose + oxygen → carbon dioxide + water + 38ATP

2) 2H₂ + O₂ → 2H₂O ΔH = -486 kj/mol

The given reaction is formation of water. In this reaction oxygen and hydrogen react to form water and 486 kj/mol is also released.

The reaction in which heat is released is called exothermic reaction.

Exothermic reaction:

The type of reactions in which energy is released are called exothermic reactions.

In this type of reaction energy needed to break the bonds are less than the energy released during the bond formation.

For example:

Chemical equation:

C + O₂ → CO₂

ΔH = -393 Kj/mol

it can be written as,

C + O₂ → CO₂ + 393 Kj/mol

Endothermic reactions:

The type of reactions in which energy is absorbed are called endothermic reactions.

In this type of reaction energy needed to break the bond are higher than the energy released during bond formation.

For example:

C + H₂O → CO + H₂

ΔH = +131 kj/mol

it can be written as,

C + H₂O + 131 kj/mol → CO + H₂

5 0

3 years ago

A sample of propane(c3h8)has 3.84x10^24 H atoms.

deff fn [24]

Answer:

A) 14. 25 × 10²³ Carbon atoms

B) 34.72 grams

Explanation:

1 molecule of Propane has 3 atoms of Carbon and 8 atoms of Hydrogen.

The sample has 3.84 × 10²⁴ H atoms.

If 8 atoms of Hydrogrn are present in 1 molecule of propane.

3.84 × 10²⁴ H atoms are present in

$\mathfrak{ \frac{3.8 }{8} \times 10 ^{24}}$

= 4.75 × 10²³ molecules of Propane.

- - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -

No. of Carbon atoms in 1 molecule of propane = 3

=> C atoms in 4.75× 10²³ molecules of Propane = 3 × 4.75 × 10²³

= 14.25 × 10²³ 

________________________________________

Gram Molecular Mass of Propane(C3H8)

= 3 × 12 + 8 × 1

= 36 + 8

= 44 g

1 mole of propane weighs 44g and has 6.02× 10²³ molecules of Propane.

=> 6.02 × 10²³ molecules of Propane weigh = 44 g

=> 4. 75 × 10²³ molecules of Propane weigh =

$\mathsf{ \frac{44 }{6.02 \times {10}^{23} } \times 4.75 \times {10}^{23} }$

$\mathsf{ = \frac{44 }{6.02 \times \cancel{{10}^{23} }} \times 4.75 \times \cancel{ {10}^{23}} }$

$\mathsf{ = \frac{44 }{6.02 } \times 4.75 }$

= 34.72 g

8 0

2 years ago

A chemist mixes sodium with water and witnesses a violent reaction between the metal and water. this is best classified as

Tema [17]

A law is statement about an observed concept. A theory involves the explanation of scientific concepts or principles. A hypothesis is the predicted explanation about some concepts that has to be tested in order to prove it to be right. An observation is the observing the results of a scientific experiment carried out to test an hypothesis.

Here the given statement 'A chemist mixes sodium with water and witnesses a violent reaction between the metal and water,' can be classified as an observation as it explains what the chemists observes as a result of his chemical experiment or test..

8 0

3 years ago