Please help me with dis

A student reduces the temperature of a 300 cm3 balloon from 60°c to 30°

FromTheMoon [43]

We can use the ideal gas equation which is expressed as PV = nRT. At a constant pressure and number of moles of the gas the ratio T/V is equal to some constant. At another set of condition of temperature, the constant is still the same. Calculations are as follows:

T1 / V1 = T2 / V2

V2 = T2 x V1 / T1

V2 = 303.15 x 300 / 333.15

V2 = 272.99 cm³

7 0

4 years ago

The atoms in a molecule are not bonded together.

vekshin1

Answer:

Compound: two or more different atoms chemically bonded together. Molecule: two or more different or same atoms chemically bonded together. Element: one single atom. A mixture contains two or more substances (elements, lattices, molecules, compounds), that are not chemically bonded together.

Explanation:

6 0

3 years ago

Nitrogen dioxide reacts with water to form nitric acid and nitrogen monoxide according to the equation: 3NO2(g)+H2O(l)→2HNO3(l)+

Vesnalui [34]

Answer:

2 mol NO2

Explanation:

3NO2(g)+H2O(l)→2HNO3(l)+NO(g)

from reaction 3 mol 1 mol

given 11 mol 3 mol

for 3 mol NO2 ----- 1 mol H2O

for x mol NO2 ----- 3 mol H2O

3:x = 1:3

x = 3 *3/1 = 9 mol NO2

So, for 3 mol H2O are needed only 9 mol NO2.

But we have 11 mol NO2. So, NO2 is in excess, and

11 mol NO2 - 9 mol NO2 = 2 mol NO2 will be left after reaction.

3 0

3 years ago

: How does the solubility of a solid in a liquid depend on temperature? How is this temperature dependence exploited to purify s

ehidna [41]

Answer:

Explanation:

Solubility of many solid in a solvent increases with increase in temperature. Increase in temperature increases kinetic energy of the solute, increasing collision and weakens the intermolecular force within the solute. This makes the solute dissolve faster in their solvents.

During recrystallization, more solutes are added to the solvent at higher temperature so that a supersaturated solution is produced on cooling. As the solution cools the over saturated solute begins to precipitate out of the solution.

Recrystallization is a form of purification if solid, as the crystalline solids continue to precipitate it reject impurities are comes out as a purer solid

3 0

3 years ago

Given the following chemical reaction: 2 O2 + CH4 CO2 + 2 H2O What mass of CH4 is required to completely react with 100 grams of

AfilCa [17]

Answer:

The mass methane (CH4) required is, 25 grams (option C)

Explanation:

Mass of oxygen gas = 100 g

Molar mass of oxygen gas = 32 g/mole

Molar mass of methane gas = 16 g/mole

Step 1: Balance the reaction

2O2 + CH4 → CO2 + 2H2O

Step 2: Calculate the moles of O2:

Moles O2 = mass of O2 / Molar mass of o2

Moles O2 = 100g / (32g/mole) = 3,125 moles

⇒From the balanced reaction we conclude that 2 moles of O2 react with 1 mole of CH4

⇒ So, 3.125 moles of O2 react with 3.125/2 = 1.563 moles of CH4

Step 3: Calculate the mass of CH4:

Mass of CH4 = moles of CH4 x Molar mass of CH4

Mass of CH4 = 1.563 moles / (16g/ moles) = 25.008 grams CH4

6 0

3 years ago