A helium balloon contains 16.9 L of helium at STP. How many atoms of helium are in the balloon

The arrows in the image show the direction in which carbon is moving Which process of the carbon cycle is indicated

s344n2d4d5 [400]

The carbon cycle involves the circulation of carbon dioxide (CO2) from the atmosphere into plants and other living organisms; the transfer of carbon from these organisms into other temporary storage pools, living or nonliving, containing organic and inorganic carbon compounds; and the return of CO2 to the atmosphere

8 0

3 years ago

Identify the main purpose of the Periodic Table. *

saw5 [17]

The periodic table is one of the most important tools in the history of chemistry. It describes the atomic properties of every known chemical element in a concise format, including the atomic number, atomic mass and relationships between the elements. Elements with similar chemical properties are arranged in columns in the periodic table.

The table thus is a quick reference as to what elements may behave the same chemically or which may have similar weights or atomic structures.

Hope this answer helps you

4 0

3 years ago

Find the enthalpy of neutralization of HCl and NaOH. 137 cm3 of 2.6 mol dm-3 hydrochloric acid was neutralized by 137 cm3 of 2.6

liraira [26]

Answer : The correct option is, (D) 89.39 KJ/mole

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=2.6mole/L\times 0.137L=0.3562mole$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.3562 mole of HCl neutralizes by 0.3562 mole of NaOH

Thus, the number of neutralized moles = 0.3562 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $137ml+137ml=274ml$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 274ml=274g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 274 g

$T_{final}$ = final temperature of water = 325.8 K

$T_{initial}$ = initial temperature of metal = 298 K

Now put all the given values in the above formula, we get:

$q=274g\times 4.18J/g^oC\times (325.8-298)K$

$q=31839.896J=31.84KJ$

Thus, the heat released during the neutralization = -31.84 KJ

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -31.84 KJ

n = number of moles used in neutralization = 0.3562 mole

$\Delta H=\frac{-31.84KJ}{0.3562mole}=-89.39KJ/mole$

The negative sign indicate the heat released during the reaction.

Therefore, the enthalpy of neutralization is, 89.39 KJ/mole

3 0

3 years ago

Will 1 gram of sugar or 1 gram of salt dissolve more quickly which one

Montano1993 [528]

1 gram of sugar because super molecules are bigger then the ions of dissolved salt

6 0

3 years ago

How many moles of hydrogen are needed to completely react with 2 moles of nitrogen

Natali5045456 [20]

Assuming ammonia is the product of this reaction:

N2+3H2--->2NH3

2 mole N2 * (3 mol H2)/(1 mol N2)= 6 mol H2

You would need 6 mol of hydrogen gas to completely react with 2 mol of nitrogen.

5 0

3 years ago