CHEMISTRY
MIDDLE SCHOOL

Answer:

Answer: The empirical formula of the compound is

Explanation:

To find the empirical formula of the compound, we follow following steps:

- Step 1: Finding the number of moles of the given elements.

To calculate the number of moles, we use the formula:

- For Calcium:

Molar mass of calcium = 40 g/mol

Given mass of calcium = 13.5 g

Putting values in above equation, we get:

- For Oxygen:

Molar mass of oxygen = 16 g/mol

Given mass of oxygen = 10.8 g

Putting values in above equation, we get:

- For Hydrogen:

Molar mass of hydrogen = 1 g/mol

Given mass of hydrogen= 0.675 g

Putting values in above equation, we get:

- Step 2: Now, to obtain the mole ratio, we divide the moles of each element by the smallest number of moles calculated.

For Ca =

For H =

For O =

The ratio of Ca : O : H = 1 : 2 : 2

- Step 3: Now, the ratio of the elements is represented as the subscripts in the empirical formula.

The formula becomes:

Hence, the empirical formula of the compound is

HIGH SCHOOL

iven the following chemical equations:I. C+ 2H_2 2 → CH_4 4 (0.22 moles of H_2 2 )II. 6CO_2 2 + 6H_2 2 O → C_6 6 H_{12} 12 O_6 6 (2.25 g of CO_2 2 )III. CH_4 4 + 2O_2 2 → CO_2 2 + 2H_2 2 O (1.25 L of CH_4 4 with density = 0.656 g/L)Which equation will have the highest number of carbon atoms produced based on the information given next to each chemical equation

Answer:

Equation (I) produced the highest number of carbon atoms.

Explanation:

For equation (I): ⇒ (0.22 moles of )

2 moles of hydrogen gas will produce 1 mole of methane gas. Therefore, 0.22 moles of hydrogen gas will produced (0.22/2) = 0.11 moles of methane gas.

Similarly, 1 mole of methane gas has one mole of carbon atom and 4 moles of hydrogen atoms. Therefore, 0.11 moles of methane gas will have 0.11 mole of carbon atom.

The number of carbon atom = (moles of carbon atom)*(Avogadro's number)

= atoms

For equation (II): ⇒

2.25 g of carbon dioxide gas = [2.25g/(44g/mol)] = 0.051 mole of carbon dioxide gas.

In equation (II), 6 moles of carbon dioxide gas produced 1 mole of glucose. Therefore, 0.051 moles of carbon dioxide gas will produce (0.051/6) = 0.0085 moles of glucose.

Similarly, 1 mole of glucose contains 6 moles of carbon atom. Therefore, 0.0085 moles of glucose will contain (0.0085*6) = 0.051 moles of carbon atom.

The number of carbon atom = atoms.

For equation (III): ⇒

1.25 L of methane gas with density of 0.656 g/L has a mass of (1.25 L*0.656 g/L) = 0.82 g of methane gas.

moles of methane gas = 0.82g/(16g/mol) = 0.051 mol

In equation (III), 1 mole of methane gas produced 1 mole of carbon dioxide gas. Therefore, 0.051 moles of methane gas produced 0.051 moles of carbon dioxide gas.

Similarly, 1 mole of carbon dioxide gas has one mole of carbon atom. Thus, 0.051 moles of carbon dioxide gas will have 0.051 moles of carbon atom.

The number of carbon atoms = atoms.

Therefore, Equation (I) produced the highest number of carbon atoms.

MIDDLE SCHOOL

Which is the electron configuration of lithium

Here we have to get the electronic configuration of lithium element.

The electronic configuration of lithium (Li) is 1s²2s¹.

The lithium posses 3 electrons. The filling up the electrons in the orbitals depends upon the number of electrons can be accommodated in the particular orbital.

We know the filling of electrons is done from the low energy orbital to high energy orbital. The energy chrome of the s, p, d and f orbitals are s

COLLEGE

How many significant figures are in the following? a) 0.1111 b) 2000 c) 35.6 d) 180,701

Answer:

a) 0.1111 : 4 significant figures

b) 2000 : 1 significant figure

c) 35.6 : 3 significant figures

d) 180,701 : 6 significant digits

Explanation:

Significant figures or digits of a number are the digits that carry meaning and contribute to the precision of the number.

a) 0.1111 : 4 significant figures, leading zeros are not significant digits.

b) 2000 : 1 significant figure, trailing zeros are not significant.

c) 35.6 : 3 significant figures, all digits are significant.

d) 180,701 : 6 significant digits, zeros between mom-zero digits are significant.

MIDDLE SCHOOL

HURRY!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! If a car is at a stop sign it has kinetic energy. Question 6 options: True False

An object at rest does not have kinetic energy, but it has potential energy