All categories

3 years ago

Why do we have a leap year in our calendar every four years?

Chemistry

1 answer:

Alla [95]3 years ago

4 0

Answer:

every 4 years we add an extra day, February 29th, to our calendars these extra days called leave days help synchronize our human created calendars with us orbit around the sun and the actual passing of our seasons

You might be interested in

<img src="https://tex.z-dn.net/?f=%5Cboxed%7B%5Crm%7BChemistry%20%5C%20Question%7D%7D" id="TexFormula1" title="\boxed{\rm{Chemis

shepuryov [24]

Answer:

Explanation:

All three lighter boron trihalides, BX3 (X = F, Cl, Br), form stable adducts with common Lewis bases. Their relative Lewis acidities can be evaluated in terms of the relative exothermicities of the adduct-forming reaction. Such measurements have revealed the following sequence for the Lewis acidity: BF3 < BCl3 < BBr3 (in other words, BBr3 is the strongest Lewis acid).

This trend is commonly attributed to the degree of π-bonding in the planar boron trihalide that would be lost upon pyramidalization (the conversion of the trigonal planar geometry to a tetrahedral one) of the BX3 molecule, which follows this trend: BF3 > BCl3 > BBr3 (that is, BBr3 is the most easily pyramidalized). The criteria for evaluating the relative strength of π-bonding are not clear, however. One suggestion is that the F atom is small compared to the larger Cl and Br atoms, and the lone pair electron in the 2pzorbital of F is readily and easily donated, and overlaps with the empty 2pz orbital of boron. As a result, the [latex]\pi[/latex] donation of F is greater than that of Cl or Br. In an alternative explanation, the low Lewis acidity for BF3 is attributed to the relative weakness of the bond in the adducts F3B-L.

3 0

2 years ago

Read 2 more answers

A 50.0 mL sample of 12.0 M HCl is diluted to 200 mL. What is true about the diluted solution?

kobusy [5.1K]

The concentration of the solution reduces and the number of moles of solute isn't affected.

Data;

V1 = 50mL
C1 = 12.0M
V2 = 200mL
C2 = ?

<h3>Facts about the diluted solution</h3>

1. When the solution is diluted, the concentration changes and this time, the concentration reduces.

Using dilution formula

$c_1 v_1 = c_2 v_2\\12 * 50 = c_2 * 200\\c_2 = \frac{600}{200} \\c_2 = 3M$

The concentration of the solution reduces.

2. The number of moles remains the same.

When a solution is diluted, the number of moles remains the same because there's no change in the mass of the solute.

Learn more on concentration of a solution here;

brainly.com/question/2201903

7 0

2 years ago

A substance that will change shape to fit its container but has a definite volume is in a phase of matter?

Leto [7]

I know water will change the shape to match the container its in if that is your question

8 0

3 years ago

Read 2 more answers

What direction do the plates have to move in order for an earthquake to occur?

Bess [88]

they would be pushing together

4 0

3 years ago

Read 2 more answers

Ice floats on water. For most other substances, however, the solid sinks in the liquid. Classify each of these statements based

sattari [20]

Answer:

1.High pressure will cause the liquid to become solid :

Describe both water and other substances

2.High pressure will cause the solid to become liquid :

It describe none : neither water nor other substances 

This statement is :False for both water and other substances

3.The solid is more dense than the liquid :

It describe other substance

This statement is :False for water but true for other substances.

4. In a phase diagram, the solid-liquid coexistence line has a negative slope.

It describes water:

This statement is :True for water because solid ice is less dense than liquid water.

False for other substance, they have positive slope

5.The molecules are closest in the liquid phase.

This statement is :False for water and other substances

6.The solid is less dense than the liquid:

It Describes water because ice is less dense than liquid water

7. In a phase diagram, the solid-liquid coexistence line has a positive slope.

It describe other substances

This statement is :True for other substances but false for water

8. The molecules are closest in the solid phase :

Describes both water and other substances

Explanation:

Answers to statement 1 , 2,5 and 8

Answers to statement 1 , 2

On increasing pressure and decreasing temperature , There occur Phase transition always for every substance :

From liquid to solid and gas to liquid

Hence,

In Both for water and other substance

High pressure will cause the liquid to become solid.

Answers to statement 5,8 :

2.The Particles of solid are closely packed hence there is maximum force of attraction between the particle of solid as compared to liquid and gases .

Hence , The molecules of both water and other substances are closest in the solid phase

This also means that in liquid molecules are far apart .

Rest statement : 3, 4 ,6 ,7 are explained below(see attached image)

The molecules are closest in the liquid phase is false statement and does not describe both water and other substance

Ice floats on water. For most other substances, however, the solid sinks in the liquid.

This can be explained using the phase diagram of water :

The line DB is = the solid-liquid coexistence line

It has negative slope because , solid ice is less dense than liquid water . That is why ice floats on water because its density is less than water

Hence Water is described truly by statement 4,6, which are :

4. the solid-liquid coexistence line has a negative slope.

6.The solid is less dense than the liquid.

Rest 3,7 = describe by other substance

other substance : Solid is more dense than the liquid ,the solid-liquid coexistence line has a positive slope

7 0

3 years ago