Which is NOT a way to accelerate an object? *

kvasek [131]

Lower than 7 is acid greater than 7 is a base

6 0

3 years ago

Imagine you needed to identify if an object has undergone a physical change or a chemical change. What information would you nee

pishuonlain [190]

How it looks. basically the thing that tells you how it change. for example if an ice cube was melted (heat), it only changed physically not chemically as the h20 molecules are still there. however lets say you burn woos— you cant get that would back. its ash now and it has changed chemically.

7 0

3 years ago

What mass of H₂ is needed to react with 8.75 g of O₂ according to the following equation: O2(g) + H2(g) → H₂O(g)?

FromTheMoon [43]

Explanation:

For reacting with 8.75 grams of oxygen, 1.08 grams of hydrogen is required.

The given balanced equation has been:

\rm O_2\;+\;2\;H_2\;\rightarrow\;H_2OO2+2H2→H2O

From the equation, 1 mole of oxygen reacts with 2 mole of hydrogen to give 1 mole of water.

The mass of oxygen has been: 8.75 g,

Moles = \rm \dfrac{weight}{molecular\;weight}molecularweightweight

Moles of oxygen = \rm \dfrac{8.75}{32}328.75

Moles of oxygen = 0.27 mol

Since,

1 mole Oxygen = 2 mole hydrogen

0.21 mol oxygen = 0.54 mol hydrogen

Mass of hydrogen = moles \times× molecular weight

Mass of hydrogen = 0.54 \times× 2

Mass of hydrogen = 1.08 grams.

Thus, for reacting with 8.75 grams of oxygen, 1.08 grams of hydrogen is required.

6 0

1 year ago

Hydrocarbons, compounds containing only carbon and hydrogen, are important in fuels.The heat of combustion of cyclopentane, C5H1

shtirl [24]

Answer : The balanced equation for the complete combustion of cyclopentane will be :

$2C_5H_{10}+15O_2\rightarrow 10CO_2+10H_2O$

Explanation :

As we know that the hydrocarbons can undergo complete or incomplete combustion that depends on the amount of oxygen available.

Complete combustion : It takes place when there is a good supply of oxygen. In this, hydrocarbon react with the oxygen to give carbon dioxide and water as a product.

The general reaction will be :

$\text{Hydrocarbon}+O_2\rightarrow CO_2+H_2O$

Incomplete combustion : It takes place when there is a poor supply of oxygen. In this, hydrocarbon react with the oxygen to give carbon monoxide, carbon dioxide and water as a product.

The general reaction will be :

$\text{Hydrocarbon}+O_2\text{(limited)}\rightarrow CO+CO_2+H_2O$

As per question, the complete combustion of cyclopentane react with oxygen to gives carbon dioxide and water as a product.

Therefore, the balanced chemical reaction will be :

$2C_5H_{10}+15O_2\rightarrow 10CO_2+10H_2O$

7 0

3 years ago

How many grams of sodium bromide must be dissolved in 400.0 g of water to produce a 0.500 molar solution?

kiruha [24]

Answer:

D. 20.6g

Explanation:

Molarity is defined as ratio between moles of solute (sodium bromide, NaBr) per liter of water.

As density of water is 1g/mL; volume of 400.0g of water is 400.0mL = 0.4000L.

That means 0.400L of 0.500M solution contains:

0.400L × (0.500mol / 1L) = <em>0.200moles of sodium bromide</em>.

In mass (NaBr = 102.9g/mol):

0.200mol NaBr × (102.9g/mol) = 20.6g of NaBr

Right answer is:

8 0

3 years ago