In the process of photosynthesis, carbon dioxide and water react chemically, with the help of sunlight, to produce oxygen

Why does it generally take more enthalpy to ignite a solid than a gas or liquid?

Anuta_ua [19.1K]

Answer:

It is due to the nature of the reactants

Explanation:

To ignite a solid, we require more heat component compared to liquids and gases. For ignition to occur, oxygen gas combines with a reactant in most cases.

Some factors affect the rate rate at which a chemical proceeds. One of the factors is the nature of reactants.

The solid phase is very slow while the gaseous phase is rapid and fast.

solid phase < liquid phase < gas phase

Gases are free and the molecules move in all direction. They easily combine and react very fast.

6 0

4 years ago

What will be the volume of a gas sample at 358 K if its volume at 255 K is 7.4 L?

Jobisdone [24]

Answer:

10.4 L

Explanation:

V1/T1=V2/T2

V2= (V1*T2)/T1

V2= (7.4L * 358K)/255K

V2=10.4 L

4 0

3 years ago

(I)how many atoms are present in 7g of lithium?

ICE Princess25 [194]

Answer :

(i) The number of atoms present in 7 g of lithium are, $6.07\times 10^{23}$

(ii) The number of atoms present in 7 g of lithium are, $1.204\times 10^{24}$

(iii) The number of moles of $F_2$ is, 1 mole

The number of moles of $CO_2$ is, 0.5 mole

The number of moles of $OH^-$ is, 1 mole

Explanation :

Part (i) :

First we have to calculate the moles of lithium.

$\text{Moles of }Li=\frac{\text{Mass of }Li}{\text{Molar mass of }Li}$

Molar mass of Li = 6.94 g/mole

$\text{Moles of }Li=\frac{7g}{6.94g/mol}=1.008mole$

Now we have to calculate the number of atoms present.

As, 1 mole of lithium contains $6.022\times 10^{23}$ number of atoms

So, 1.008 mole of lithium contains $1.008\times 6.022\times 10^{23}=6.07\times 10^{23}$ number of atoms

Thus, the number of atoms present in 7 g of lithium are, $6.07\times 10^{23}$

Part (ii) :

First we have to calculate the moles of carbon.

$\text{Moles of }C=\frac{\text{Mass of }C}{\text{Molar mass of }C}$

Molar mass of C = 12 g/mole

$\text{Moles of }C=\frac{24g}{12g/mol}=2mole$

Now we have to calculate the number of atoms present.

As, 1 mole of carbon contains $6.022\times 10^{23}$ number of atoms

So, 2 mole of carbon contains $2\times 6.022\times 10^{23}=1.204\times 10^{24}$ number of atoms

Thus, the number of atoms present in 7 g of lithium are, $1.204\times 10^{24}$

Part (iii) :

To calculate the moles of $F_2$ :

$\text{Moles of }F_2=\frac{\text{Mass of }F_2}{\text{Molar mass of }F_2}$

Molar mass of $F_2$ = 38 g/mole

$\text{Moles of }F_2=\frac{19g}{19g/mol}=1mole$

Thus, the number of moles of $F_2$ is, 1 mole

To calculate the moles of $CO_2$ :

$\text{Moles of }CO_2=\frac{\text{Mass of }CO_2}{\text{Molar mass of }CO_2}$

Molar mass of $CO_2$ = 44 g/mole

$\text{Moles of }CO_2=\frac{22g}{44g/mol}=0.5mole$

Thus, the number of moles of $CO_2$ is, 0.5 mole

To calculate the moles of $OH^-$ ions :

$\text{Moles of }OH^-=\frac{\text{Mass of }OH^-}{\text{Molar mass of }OH^-}$

Molar mass of $OH^-$ = 17 g/mole

$\text{Moles of }OH^-=\frac{17g}{17g/mol}=1mole$

Thus, the number of moles of $OH^-$ is, 1 mole

4 0

3 years ago

How many molecules are there in 4.00 l of oxygen gas at 500.∘ c and 50.0 torr?

Oliga [24]

From the ideal gas law
pv=nRT , n is therefore PV/RT
R is the
R is gas constant =62.364 torr/mol/k
P=500torr
V=4.00l
T=500+273=773k
n={(500 torr x 4.00l)/(62.364 x773k)}=0.041moles
the number of molecules=moles x avorgadro costant that is 6.022x10^23)
6.022 x 10^23) x0.041=2.469 x10^22molecules

3 0

3 years ago

What is the shape of a molecule containing three covalent bonds with one unshared pair?

Schach [20]

pyramidal, if you have a molecule kit, i would strongly recommend watching a video of someone using a kit explaining the different shapes and following along. It helps a lot!

7 0

3 years ago