All categories

2 years ago

Please help???? i dont know this

Chemistry

2 answers:

xeze [42]2 years ago

7 0

Answer:

a and b

Explanation:

Nesterboy [21]2 years ago

4 0

Answer:

The after-rain smell is produced by an interaction between rain and the oils released by plants. Due to chemical reaction between the rain water and oils secreted out by the plants

A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released. When vinegar reacts with baking soda carbon-dioxide gas is released.

The Statue of Liberty has turned green over time due to the reaction of copper with ,oxygen,carbon dioxide and water.

Explanation:

Chemical change is defined as those change in which arrangement of atoms present in the substance changes and leads to formation of new substance.

The after-rain smell is produced by an interaction between rain and the oils released by plants. Due to chemical reaction between the rain water and oils secreted out by the plants

A homemade volcano can be created by combining baking soda and vinegar. When it erupts, carbon dioxide gas is released. When vinegar reacts with baking soda carbon-dioxide gas is released.

$CH_{3} COOH+ NaHCO_3$ → $CO_2+H_2O+CH_3COONa$

The Statue of Liberty has turned green over time due to the reaction of copper with ,oxygen,carbon dioxide and water.

$Cu+O_2+CO_2+H_2O$ → $Cu_2(OH)_2CO_3$

Physical change is defined as those changes which leads to change in shape, size or state of the substance changes. No new substance is formed.

You might be interested in

12.Calculate the wavelength of an object moving with a velocity of 5 x105 m s-1

uranmaximum [27]

Answer:

Wavelength, $\lambda=3.3\times 10^{-18}\ m$

Explanation:

We have,

Velocity of the object, $v=5\times 10^5\ m/s$

Mass of the object, $m=4\times 10^{-22}\ kg$

It is required to find the wavelength of the object. The relation between wavelength and velocity of the object is given by :

$\lambda=\dfrac{h}{mv}$

h is Planck's constant

$\lambda=\dfrac{6.6\times 10^{-34}}{4\times 10^{-22}\times 5\times 10^5}\\\\\lambda=3.3\times 10^{-18}\ m$

So, the wavelength of the object is $3.3\times 10^{-18}\ m$ .

5 0

3 years ago

PLEASE HELP!

Tanzania [10]

Molar mass:

KCl = 74.55 g/mol

KClO3 = 122. 55 g/mol

<span>Calculation of the mass of KClO3 :</span>

<span>2 KClO3 = 2 KCl + 3 O2</span>

2* 122.55 g KClO3 ------------------ 2 * 74.55 g KCl
mass KClO3 ?? --------------------- 25.6 g KCl

mass KClO3 = 25.6 * 2 * 122.55 / 2 * 74.55

mass KClO3 = 6274.56 / 149.1

mass = 42.082 g of KClO3

Therefore:

1 mole KClO3 ---------------------- 122.55 g
?? moles KClO3 ------------------- 42.082 g

moles KClO3 = 42.082 * 1 / 122.55

moles KClO3 = 42.082 / 122.55

=> 0.343 moles of KClO3

Answer C

hope this helps!

3 0

3 years ago

Water boils at rate of ........and freeze at ........

Schach [20]

100 degree celcius and 0 degree Celsius

7 0

3 years ago

2al2o3 4al 3o2 what is the mole ra#tio of aluminum to oxygen is 4:3

erik [133]

In the reaction represented by the equation 2Al2O3-->4Al+3O2, what is the mole ratio of aluminum to oxygen?

4:3

8 0

3 years ago

MyRoad is a(n):

Assoli18 [71]

c. online college and career planning resource you can access once you take the PSAT.

Explanation:

MyRoad is an online platform where college and career planning resources can be accessed when the PSAT has been taken.

It provides an online mentor-ship and guidance for approaching the more robust college life.

The platform allows diverse students to access useful information about their intended colleges.

It also helps in determining career choices and a host of other resources.

5 0

3 years ago