All categories

4 years ago

What is the common English unit of length?

1 answer:

6 0

Depending on the size of the object, that system may describe it
in terms of inches, feet, yards, chains, rods, or miles.

You might be interested in

K2HPO4 is a highly water-soluble salt. It can be used as a buffering agent, food additive, or

borishaifa [10]

Answer:

91.7%

Explanation:

3 0

3 years ago

Read 2 more answers

In which pattern, periodic table was arranged?

aksik [14]

Answer: Elements are arranged from left to right and top to bottom in order of increasing atomic number.

Explanation: Order generally coincides with increasing atomic mass.

3 0

3 years ago

What are the purposes of a chemical equation? Check all that apply.

Jlenok [28]

Answer:

to show how substances in a chemical reaction interact

to shorten the explanation of a chemical reaction

to help keep track of atoms in a chemical reaction

Explanation:

5 0

3 years ago

3) In 5 electron group molecules, what is the difference between axial and equatorial positions? Which groups are removed as lon

shusha [124]

The axial positions the bond angle is 120 degrees and in equatorial positions the bond angle is 90 degrees.

Functional groups on central atom gets reduce if lone pairs are added.

Explanation:

The number of lone pairs and base pairs of electrons tells the geometry of the molecule.

VSEPR Theory helps to know the lone pairs and bond pair electrons on the centre atom of the molecule.

Example of molecule containing 5 electron pairs can have four bond pairs and 1 lone pair.

eg: Cl $F_{3}$

the repulsion is shown as

lp-lp> lp-bp>bp-bp

These are in equatorial position because of the repulsion of lone pairs.

It can have 2 lone pairs and 3 bond pairs. eg. Xe $F_{2}$

Lone pairs in this is also in equatorial position as

lp-lp> lp-bp> bp-bp

In axial positions the bond angle is 120 degrees

in equatorial positions the bond angle is 90 degrees, due to the repulsion in lone pair of electrons.

If 1 lone pair is there it can be replaced by bonding with hydrogen.

If 2 lone pairs are there then bonding with oxygen is there. The covalent bond is formed.

7 0

3 years ago

34. 3.15 mol of an unknown solid is placed into enough water to make 150.0 mL of solution. The solution's temperature increases

Digiron [165]

Answer:

ΔH = 2.68kJ/mol

Explanation:

The ΔH of dissolution of a reaction is defined as the heat produced per mole of reaction. We have 3.15 moles of the solid, to find the heat produced we need to use the equation:

q = m*S*ΔT

Where q is heat of reaction in J,

m is the mass of the solution in g,

S is specific heat of the solution = 4.184J/g°C

ΔT is change in temperature = 11.21°C

The mass of the solution is obtained from the volume and the density as follows:

150.0mL * (1.20g/mL) = 180.0g

Replacing:

q = 180.0g*4.184J/g°C*11.21°C

q = 8442J

q = 8.44kJ when 3.15 moles of the solid react.

The ΔH of the reaction is:

8.44kJ/3.15 mol

= 2.68kJ/mol

5 0

3 years ago