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# Questions posted in Chemistry

## Consider the reaction when aqueous solutions of copper(ii) nitrate and nickel(ii) chloride are combined.

Answer : The reaction that will occur when you combine the aqueous solutions of copper nitrate with nickel chloride is a displacement reaction.

It explained below with the reaction :-

Explanation : The reaction will give the major product as copper chloride in the form of solid. Rest all the ions will  remain in the aqueous form.

## What is the fundamental difference between covalent and ionic bonding? in a covalent bond, the partners share a pair of electrons; in an ionic bond, one partner accepts electrons from the other. in covalent bonding, both partners end up with filled outer electron shells; in ionic bonding, one partner does and the other does not. covalent bonding involves only the outermost electron shell; ionic bonding also involves the next electron shell inside the outermost shell. covalent bonds form between atoms of the same element; ionic bonds form between atoms of different elements?

In covalent the partners share while in ionic they give out and accept electrons
ionic are formed between a non metal and metal while in covalent are formed between two non metals

## What is the molarity of a 27.0% (v/v) aqueous ethanol solution? the density of ethanol (c2h6o, molar mass 46.07 g/mol) is 0.790 g/ml?

The  molarity  of a  27%(v/v) aqueous  ethanol  solution  is 4.63 M

calculation
convert  27%(v/v) to  fraction  = 27ml/100 ml

use  density to  convert  27ml  to grams =  27 ml  x0.79 g/ml = 21.33 g

find  the number  of moles  of C2H6O

moles = mass/molar mass of C2H6O(46.07 g/mol)

moles is therefore = 21.33 g /46.07 g/mol =0.463  moles

find the  molarity =   moles /volume in liters

volume in liter =  100 ml/1000 = 0.1 L

molarity  is therefore =  0.463 mole/0.1 L = 4.63  M

## The heart is classified as a(n)_____.A.cell B.organ C.tissue D.system

B. Organ

Since the heart is made up of different tissues that are made out of cells

## The element 1s2 2s2 2p6 3s2 3p6 represents which noble gas

It represents Argon [Ar]

## Define melting point

The temperature at which a given solid will melt, eventually.

## What are the concentrations of h3o+ and oh− in tomatoes that have a ph of 4.22? ## Water is separated into oxygen gas (o2) and hydrogen gas (h2) using a process called electrolysis. after electrolysis, 0.15 moles of hydrogen gas are collected at stp. what is the volume of 0.15 moles of hydrogen gas obtained at stp?

Volume of 1 mole of any gas under STP = 22.4 L,
so
0.15 mol*22.4 L/1 mol = 3.36 L of H2

## Why can an increase in temperature lead to more effective collisions between reactant particles and an increase in the rate of a chemical reaction?the activation energy of the reaction increases.the activation energy of the reaction decreases.the number of molecules with sufficient energy to react increases.the number of molecules with sufficient energy to react decreases?

The answer to this question is that the number of molecules with sufficient energy to react increases. The lack of reactivity at room temperature is not due to lack of collision. Since high temperatures favor fast rate of reactions, energy in a given molecule determines whether the molecule will react.
At some temperature, some molecules react and some molecules do not react. There must be a continuous distribution of energy between the molecules.
As the system temperature rises, the average energy in the system also increases. The increase in reaction rate due to temperature increase is mainly due to an increase in the number of molecules with sufficient energy to react, not an increase in the number of collisions.

## Why must the beakers used to carry out each reaction be completely dry?

The substance (water) used to clean the beaker could effect the outcome of the experiment.

## When the equation below is balanced, the coefficient of sulfuric acid, h2so4 is: nacn + h2so4 → na2so4 + hcn?

2NaCN + (1)H2SO4 → Na2SO4 + 2HCN

The coefficient of sulfuric acid is 1.

## Which element has atoms that can form halide ions?iodinesilverstrontiumxenon?

Iodine which is a halogen only can form halide ion with another element

## What is the process of how water freezes

Water will lose heat and turn into solid from liquid. The process is then called freezing

## How many carbons would the following molecules contain? A) A straight chain Alkene with 14 carbons and 3 double bonds B) A straight chain Alkyne with 9 carbons and 2 triple bonds

A is 14
B is 9    is it right

## Why does titanium carbide have a high melting point?

Titanium carbide has a high melting point BECAUSE OF THE STRONG FORCE OF ATTRACTION BETWEEN THE COMPONENT PARTICLES AND THE TIGHTLY PACKED CRYSTAL STRUCTURE OF THE SUBSTANCE. Titanium carbide is used for cutting tools because of its hardness; it is one of the hardest naturally occurring carbide known. It is also used as abrasion resistant surface coating for metals.

## In a balanced reaction NH3+ H2O—> NH3OH how many hydrogens atoms are gained in the reaction

There is no hydrogen gained it is a combination reaction

## What is the name for a molecule that is made of two sugers monomers boned together?

2 sugar molecules are reffered to as a disaccharide

## NF3 Spell out the full name of the compound.

Nitrogen triflouride

## If you made up a solution of NaOH by adding 0.010 mole of solid NaOH to 1.0 liter of distilled water, what would be the concentration of the OH-(aq)?

Explantion :

NaOH is a strong base which fully dissociates into its ions in water as Na and OH⁻.

NaOH(s) → Na⁺(aq) + OH⁻(aq)

The stoichiometric ratio between NaOH(s) and OH(aq) is 1 : 1.

Hence,
moles of OH⁻(aq) = moles of NaOH(s)
= 0.010 mol

Concentration (M) = moles of solute (mol) / volume of the solution (L)

Hence,
concentration of OH⁻(aq) = 0.010 mol / 1.0 L
= 0.01 M

## What word describes the splitting of a larger atom into smaller ones?

Atomic fission is the term used

## When the pressure that a gas exerts on a sealed container changes from 893 mm hg to 778 mm hg, the temperature changes from 49.3 degrees C to degrees C?

Answer: The final temperature of the gas is 7.58 °C.

Explanation: We are given initial and final pressure of the system and we need to find the final temperature of the system.

To calculate it, we use the equation given by Gay-Lussac.

His law states that pressure is directly related to the temperature of the gas. Or, where, = initial pressure = 893 mmHg = 1.175atm (Conversion factor: 1atm = 760mmHg) = initial temperature = 49.3°C = [49.3 + 273.15]K = 322.45K = Final pressure = 778mmHg = 1.023atm = Final temperature = ?°C

Putting values in above equation, we get: Converting Final temperature from kelvin to degree Celsius. Hence, the final temperature of the gas is 7.58 °C.

## Balance the following reaction. A coefficient of "1" is understood. Choose option "blank" for the correct answer if the coefficient is "1." Ca(OH)2 + H3PO4 → Ca3(PO4)2 + H2O

Explanation:

A balanced equation is the one which contains equal number of atoms on both reactant and product side.

For example, Number of atoms on reactant side are as follows.

• Ca = 1
• O = 6
• H = 5
• P = 1

Number of atoms on product side are as follows.

• Ca = 3
• O = 9
• H = 2
• P = 2

Therefore, to balance the chemical equation multiply by 3 and multiply by 2 on reactant side. Whereas multiply by 6 on product side.

Hence, the balanced chemical equation will be as follows. ## What is the mass of a 12.31 cm 3 piece of copper having a density of 8.96g/cm3

You have 12.31 times more copper than 1 cm3
So:
12.31*8.96=110.30 g

## What is the name for this?

Molecue?or molecule chain?

## Why do toasters always have a setting that burns the toast to a horrible crisp, which no decent human being would eat?

Probably just to see how burnt the food can get

## What is the term for a solid that forms when two liquids are mixed together

a precipitate

i go to k12 so yeah

## Which of the following chemical formula show an iconic compound

This question comes with this list of answer choices:

A. CO₂

B.N₂O

C.NaCl

D.C₆H₁₂O₆

Justification.

1) When two diferent elements join together chemically they can form either a covalent bond or a ionic bond.

2) When the bonds are covalents the compound is called covalent, when the bonds are ionics the compound is called ionic.

3) To predict whether the compound is ionic or covalent, you must see the electronegativities of the elements.

4) Ionic compounds require the formation of ions, a posititve ion and a negative ion. The positive ion is formed when the element loses one or more electrons. The negative ion is formed when the element gains one or more electrons.

Then, in the formation of a ionic compound it is implicit the exchange of electrons (one element gains the electrons that the other lose) and this is possible, when the difference in electronegativities are high enough.

5) So, you must look at the electronegativities to make your prediction. In the given options, the compounds of the options A, B and D are between non-metals. Then, you can predict that their electronegativities are not as much differet as to form ions. They will form covalent bonds.

6) Being sodium and chloride a metal and non-metal, you can expect that their electronegativities differ quite enough to form the ionic bond (this is not true for any pair of non-metal and metal elements, but being them the only pair of metal - non metal elements, this is the only option).

This leads to the conclusion that the NaCl formula shows an ionic compound, and is the answer.

## PLEASE HELP ME! WILL GIVE BRAINLEST! I need this ASAP!Use the slide and count how many of each atom you see. Lesson 5.03 includes chemical formulas.For reference, here are the three formulas in the pre-activity:Al(C2H5)2OCl3 BCl3 H2O + H+

1. Al(C₂H₅)₂OCl₃

Al(C₂H₅)₂OCl₃ is made from 5 different elements. They are Al, C, H, O and Cl. Number of atoms in each element can be found as follows.

number of Al atoms = 1
number of C atoms = 2 x 2 = 4
number of H atoms = 5 x 2 = 10
number of O atoms = 1
number of Cl atoms = 3

Total number of atoms = 1 + 4 + 10 + 1 + 3 = 19

2.
BCl

BCl
₃ is a simple neutral molecule. It consists of 2 different elements as B and Cl. Total number of atoms is 4. Number of atoms can be calculated as follows.

number of B atoms = 1
number of Cl atoms = 3

Total number of atoms = 1 + 3 = 4

3.
HO + H

H₂O makes H₃O⁺ (hydronium ion) with H⁺ which is a positive ion. H₃O⁺ consists of two different elements as H and O. Number of atoms are as follows.

number of H atoms = 3
number of atoms = 1

Total number of atoms = 3 + 1 = 4