6. The variable that a scientist changes on purpose to test a hypothesis is the

For the reaction below, identify the excess reactant when 4.35 g of hydrogen reacts with 30.75 g of iodine to produce hydrogen i

kogti [31]

The excess reactant when 4.35 g of hydrogen reacts with 30.75g of hydrogen iodide is hydrogen

<h3>calculation</h3>

write the equation for the reaction

H2(g) + I2 (g) → 2HI (g)

find the mole of each reactant

moles = mass/molar mass

moles of H2= 4.35 g/2 g/mol= 2.175 moles

moles o I2 = 30.75 g/ 254 g/mo=0.1211 moles

0.1211 moles of I2 reacted with 0.1211 moles of H2 but there are more moles of H2 there Hydrogen was in excess

6 0

4 years ago

What is a decay series?

Ulleksa [173]

Answer:

a chain of decays that result in a stable nucleus

Explanation:

Decay series is a series of decay in which radioactive element is decomposed in different elements until it produces one stable atom.

5 0

3 years ago

Read 2 more answers

Is O2 always a double bond?

Dima020 [189]

O-O single bonds and H-O single bonds in $\text{H}_2\text{O}_2$ molecules.
H-O single bonds in $\text{H}_2\text{O}$ molecules.
O=O double bonds in $\text{O}_2$ molecules.

<h3>Explanation</h3>

How many valence electrons do atoms in each molecule need for them to be stable?

Each H atom needs two valence electrons to be stable.
Each atom of an element other than H needs eight valence electron to be stable.

There are two H atoms and two O atoms in an $\text{H}_2\text{O}_2$ molecule. Atoms in each $\text{H}_2\text{O}_2$ need $2 \times 1 + 2\times 2 = 6$ more electrons to be stable.
There are two H atoms and one O atom in an $\text{H}_2\text{O}$ molecule. Atoms in each $\text{H}_2\text{O}$ molecule need $2 \times 1 + 2= 4$ more electrons to be stable.
There are two O atoms in an $\text{O}_2$ molecule. Atoms in each $\text{O}_2$ molecule need $2 \times 2 = 4$ more electrons to be stable.

How many chemical bonds in each molecule?

Each chemical bond adds one valence electron to each bonding atom. Each chemical bond connects two atoms. As a result, each chemical bond adds two valence electrons to the molecule.

Each $\text{H}_2\text{O}_2$ molecule needs $6 / 2 = 3$ chemical bonds.
Each $\text{H}_2\text{O}$ molecule needs $4 / 2 = 2$ chemical bonds.
Each $\text{O}_2$ molecule needs $4 /2= 2$ chemical bonds.

What chemical bonds are these? Again, each H atom needs only one more valence electron to be stable. It will share only one electron with O and form one H-O bond. The rest of the chemical bonds are between O atoms.

There are two H atoms in each $\text{H}_2\text{O}_2$ molecule, which form two H-O bonds. Two of the three chemical bonds in this molecule are H-O. The other is an O-O single bond between the two O atoms.
There are two H atoms in each $\text{H}_2\text{O}$ molecule, which form two H-O bonds. Both chemical bonds in this molecule are H-O. There's no O-O bond in this molecule.
There is no H atom in $\text{O}_2$ molecules. Both chemical bonds are between O atoms. However, there are only two O atoms. There must be two chemical bonds between the two O atoms. That bond will be an O-O double bond.

3 0

3 years ago

Read 2 more answers

Dustin is mixing concrete. A formula for concrete calls for 3/8 gal of water. Dustin wants to make 7/9 more concrete than the fo

slava [35]

We can use a ratio to solve this question. Lets refer to the amount formed by the formula as a serving
1 serving needs 3/8 gal
We want to create 7/9 servings extra, so
1 + 7/9 = 16/7
1 : 3/8
16/7 : x
1/(3/8) = (16/7) / x
8 / 3 = 16x / 7
x = 7/6
He needs to use 7/6 gallons of water.

5 0

3 years ago

You have 100 grams of potassium fluoride (KF) .

laiz [17]

Answer:

Option C = 1.72 mol

Explanation:

Given data:

Mass of KF = 100 g

Moles of KF = ?

Solution:

First of all we have to calculate the molar mass of KF.

Molar mass of KF = 39.0983 g/mol + 18.998403 g/mol

Molar mass of KF = 58. 0967 g/mol

Formula:

Number of moles = mass/molar mass

Number of moles = 100 g/ 58.0967 g/mol

Number of moles = 1.72 mol

6 0

3 years ago