help please bjfkboweugfowbs

Help Please Bjfkboweugfowbs

Answers

Answer 1

Answer:

B is correct answer because The enthalpy is negative so this means the reaction produces heat and the reaction is exothermic


Related Questions

which states of matter can flow from one place to another​

Answers

Answer:

Liquid

Explanation:

Quite an easy question!

Answer:

Liquid

Explanation:

I was passing by lol

Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0012 % Pb by mass. What volume of the water in milliliters contains 100 mg of Pb

Answers

Answer:

8.3 × 10³ mL

Explanation:

Step 1: Calculate the mass of water that contains 100 mg of Pb

The concentration of Pb in the sample is 0.0012% by mass, that is, there are 0.0012 g of Pb every 100 g of water. The mass of water that contains 100 mg (0.100 g) of Pb is:

0.100 g Pb × 100 g Water/0.0012 g Pb = 8.3 × 10³ g Water

Step 2: Calculate the volume corresponding to 8.3 × 10³ g of water

Since the solution is diluted, we will assume the density of the sample is equal than the density of water (1 g/mL).

8.3 × 10³ g × 1 mL/1 g = 8.3 × 10³ mL

The volume of the water in milliliters contains 100 mg of Pb is;

V =  8.3 × 10³ mL

Volume of Solution

We are given the concentration of Pb in the sample as 0.0012% by mass.

That means that there are 0.0012 g of Pb in every 100 g of water.

Thus, the mass of water that contains 100 mg (0.100 g) of Pb is calculated as;

(0.100 g Pb × 100 g of Water)/0.0012 g of Pb = 8.3 × 10³ g of Water

Now, we know that the density of water (1 g/mL) but we are not given the density of the sample.

Thus, since the solution is diluted we can equally say that;

Density of sample = 1 g/mL

Formula for Volume is;

V = mass/density

Thus;

V = 8.3 × 10³ g/1 g/mL

V = 8.3 × 10³ mL

Read more about Volume of solution at; https://brainly.com/question/17055828

Which would most likely be reduced when combined with Cu(s)?
A. Hg
B. Mg2+
C. Au+
D. Zn2+

Answers

Answer:

mg2+ because it is a very good idea

An atom has9 electrons and 9 protons at the start. If it loses 2 electrons, what would the net charge on the atom be

Answers

Answer:

i hope it will help you

Explanation:

there will be 7 electrons and 9 protons will have 2+ charge.

The most common carrier of communicable diseases are
a.cockroach
b.housefly
c.mosquito
d.spider​

Answers

housefly

Explanation:

Because it one of the affective vector of disease carrier and it always roam towards wastes and dirty materials likely to get attracted . And it carries contagious disease from hospitals , infected patients , etc .

Hydrogen gas (H2) is a promising alternative to fossil fuels. How many molecules are present in 1.0 kg of hydrogen gas

Answers

Answer:

3.01×10²⁶ molecules

Explanation:

From the question given above, the following data were obtained:

Mass of H₂ = 1 Kg

Number of molecules =?

From Avogadro's hypothesis,

1 mole of H₂ = 6.02×10²³ molecules

But 1 mole of H₂ = 2 × 1 = 2 g

Now, we shall determine the number of molecules present in 1 Kg (i.e 1000 g) of H₂ as follow:

From Avogadro's hypothesis,

2 g of H₂ = 6.02×10²³ molecules

Therefore,

1000 g of H₂ = 1000 × 6.02×10²³ / 2

1000 g of H₂ = 3.01×10²⁶ molecules

Thus, the number of molecules present in 1 Kg (i.e 1000 g) of H₂ is 3.01×10²⁶ molecules

What is the wavelength of a wave that has a frequency of 6.1⁢ x⁢ 109⁢ ⁢Hz ? c⁢ = λυ where c = 2.998 x 108⁢ m/s
a. 20.4 m
b. 2.04 m
c. 0.49 m
d. 0.049 m

Answers

Answer:

Wavelength = 0.049 m

Explanation:

Given that,

The frequency of a wave,[tex]f=6.1\times 10^9\ Hz[/tex]

We need to find the wavelength of the wave. We know that,

[tex]c=f\lambda\\\\\lambda=\dfrac{c}{f}\\\\\lambda=\dfrac{2.998 \times 10^8}{6.1\times 10^9}\\\\\lambda=0.049\ m[/tex]

So, the wavelength of the wave is 0.049 m.

please help. need this asap!!

Answers

Answer:

E.....Na2I.,.

Explanation:

Cuz sodium has a Vallency..1......lodide has Vallency 2

Metals like potassium and sodium are kept in paroffin oil. Why?​

Answers

Answer:

because they are high reactive to the air thats why we keep them in paroffin oil

Why Should a magnesium ribbon be cleaned before burning ?​

Answers

A magnesium ribbon is cleaned to remove the protective layer of basic magnesium carbonate from its surface, so that it may readily combine with the oxygen in air (on heating).

Answer:

Magnesium gets covered with a layer of magnesium oxide when kept in air for a long time. This layer hinders the burning of magnesium. Hence, it is to be cleaned before burning.

Because electrons are orbiting the nucleus, the nucleus is stationary

true or false​

Answers

Answer:

false, The nucleus of atoms still move around like crazy, it's just the electrons move more.

Can anyone answer these 4 questions?​

Answers

Answer:

1. Na2CO3 + 2HCl --> 2NaCl + CO2 + H2O

2. 2NaOH + H2SO4 --> Na2SO4 + H2O

3. CaCO3 + 2HCl --> CaCl2 + CO2 + H2O

4. 4Na + O2 --> 2Na2O

(Please help)
1.what is the most common isotope for element x

2.calculate the average atomic mass for element x

Answers

Answer:

1. Isotope with mass number 39.

2. 39.02g/mol

Explanation:

1. The most common isotope is the isotope in the higher proportion, that is:

Isotope with mass number 39.

2. The average atomic mass is the sum of the masses times their abundance. For the element X:

Average atomic mass:

38*0.0967 + 39*0.7868 + 40*0.1134 + 41*0.0031

= 39.02g/mol

Select the correct answer.
0.22 M
HCI
Unknown
LiOH
What is the concentration of the base (LIOH) in this titration?
1.0 ml
0.5 ml
Initial
burette
reading
Final
burette
reading
13.3 ml
18.5 ml
OA
0.16 M
ОВ.
0.15 M
OC. 0.22 M
OD
18 M
O E
0.5 M
Daset

Answers

Answer:

=0.15M

Explanation:

To get the moles of the unknown LiOH, calculate the number of moles of HCl in 12.3mL.

Using the stoichiometric coefficient, mole ratio 1:1.

This means that the number of moles is the same. This number of moles is contained in 18mL. Then Calculate the molarity (concentration) which is in 1000mL

See the explanation from the image I have shared with you for calculations.

How many moles of water vapor are formed. when 10 litres of butane gas c4h10 is burned in oxygen at STP ​

Answers

Using the idea of the  molar volume of butane gas, we have 2.23 moles of water vapor.

What is a reaction equation?

The term reaction equation shows the conversion of reactants to products. First of all, we must get down the reaction equation as follows;

C4H10(g) + 13/2O2(g) ----> 4CO2 (g) + 5H2O(g)

From the balanced reaction equation;

1 mole of  butane gas yields 5 moles of water vapor. Since 1 mole of butane gas occupies 22.4 L. Hence;

22.4 L of butane yields 5 moles of water vapor

10 L of butane gas yields 10 L * 5 moles/22.4 L = 2.23 moles

Learn more about butane gas:https://brainly.com/question/6665698

can someone help me?​

Answers

Answer:

1: because phosphate contain oxide ions so that is base character

Which statement is the best description of a chemical bond

Answers

Answer:

What are your given options? I can't answer unless I know those :)

Explanation:

7. (a) Using two examples, explain how covalent compounds are formed. [4 marks]
(b) State three physical properties of covalent compounds. [3 marks]
(c) Describe an experiment how you can carry out an experiment to investigate one of the properties mentioned above. [3 marks]

8. (a) Using two examples, explain how covalent compounds are formed. [14 marks]
(b) State three physical properties of covalent compounds.[3 marks]
Describe an experiment how you can carry out an experiment to investigate one of the properties mentioned above. [3 marks]​

Answers

Answer; a) Covalent compound are formed when atoms of different molecules share electrons in order to be stable either by losing or gaining electrons

eg.. HCL hydrogen chloride , a chlorine atom has 7 electrons on its outer shell and hydrogen has 1 so when this two pair they become covalently bonded. chlorine shares one electron with the hydrogen atom ,thus to say both now have a stable arrangement of electron in their outer shell.

methane CH4 the carbon atom has 4 electrons and hydrogen has 1 so carbon would need 4 more and hydrogen would need 1 more so carbon pairs with 4 hydrogen atoms making it 8 and hydrogen 2 so they now have a stable arrangement ,thus the carbon atom shares with 4 hydrogen atoms.

b) some physical properties are

i)they have low melting and boiling points

ii)their insolubility in water

iii) they are non conductors of electricity

c) an experiment using their melting and boiling point

EXPERIMENT; lets use the covalent molecule carbon monoxide CO

when you apply heat and it tend to melt at a -199 degree celsius then it is a covalent molecule

and when it starts to boil at -191 degree celsuis then its sure a carbon monoxide covalent molecule

explanation; the reason for its low melting point and boiling point is because the attraction between the molecule is very low so it doesn't need much energy to break up the lattice between them.

HOPE THIS HELP if you need more explanation feel free to comment in the comment section

An enclosed vessel contains 2.5g of 9b nitrogen and 13.3g of chlorine at s.T.P. Of What will be the partial pressure of the Il nitrogen if the temperature is raised to b 180C

Answers

Answer:

0.535 atm

Explanation:

Since the volume of the tank is constant, we use Gay- Lussac's law to find the pressure at 180°C.

So, P₁/T₁ = P₂/T₂ where P₁ = pressure at S.T.P = 1 atm, T₁ = temperature at S.T.P = 273.15 K, P₂ = pressure of gas at 180 °C and T₂ = 180 °C = 273.15 + 180 K = 453.15 K

So, P₁/T₁ = P₂/T₂

P₂ = P₁T₂/T₁

Substituting the values of the variables into the equation, we have

P₂ = P₁T₂/T₁

P₂ = 1 atm × 453.15 K/273.15 K

P₂ = 1 atm × 1.66

P₂ = 1.66 atm

We now need to find the total number of moles of each gas present

number of moles of nitrogen = mass of nitrogen, m/molar mass of nitrogen molecule M

n = m/M

m = 2.5 g and M = 2 × atomic mass of nitrogen (since it is diatomic) = 2 × 14 g/mol = 28 g/mol

So, n = 2.5 g/28 g/mol

n = 0.089 mol

number of moles of chlorine, n' = mass of chlorine, m'/molar mass of chlorine molecule M'

n' = m'/M'

m' = 13.3 g and M = 2 × atomic mass of chlorine (since it is diatomic) = 2 × 35.5 g/mol = 71 g/mol

So, n' = 13.3 g/71 g/mol

n' = 0.187 mol

So, the total number of moles of gas present is n" = n + n' = 0.089 mol + 0.187 mol = 0.276 mol

So, the partial pressure due to nitrogen gas, P = mole fraction of nitrogen × pressure of gas at 180 °C

P = n/n" × P₂

P = 0.089 mol/0.276 mol × 1.66 atm

P = 0.322 × 1.66 atm

P = 0.535 atm

PLEASE HELP ASAP!!!!!!!!

Answers

Answer:

ouch......it's kinda a practical question..

Answer: ?

Explanation: what was the answer?

Which is TRUE about the structure of the atom? Select all that apply.

a
the densest part of the atom is the nucleus of the atom
b
the outermost part of the atom is where electrons are found
c
the nucleus of the atom is where protons and neutrons are found.
d
the outer part of the atom is called the antinucleus.
e
the nucleus of the atom has a diameter of about 10-10 m.

Answers

A. The densest part of the atom ie the nucleus of the atom

A toy plane has a mass of 2.5kg and is 18 m above the ground. It is moving 4.5 m/s.

how much mechanical energy does the toy have?
A. 416J
B. 441J
C. 466J
D. 491J

Answers

Answer:

466J (c)

Explanation:

Mechanical Energy= Kinetic+Potential

Potential energy= mgh

Plug in givens

mgh=2.5*18*9.8=441J

Kinetic Energy = 1/2mv^2

Plug in givens

1/2mv^2= 1/2(2.5)(4.5)^2= 25.3125J

Mechanical energy= 441J+25.3125J=466.3125J or 466J

describe the formation of ionic bonds in potassium chloride compound (5 marks)

Answers

Answer:

When the two atoms are in contact, potassium readily transfers its outer electron to chlorine which readily accepts it, resulting in both atoms achieving a state of eight outermost electrons. With this electron transfer, the ionic bond in KCl is formed.

How are carbon-based molecules suited for sustaining life?

Answers

[tex]\huge\fcolorbox{red}{pink}{Answer ♥}[/tex]

Life on Earth is based on carbon, likely because each carbon atom can form bonds with up to four other atoms simultaneously. This quality makes carbon well-suited to form the long chains of molecules that serve as the basis for life as we know it, such as proteins and DNA.

Hope it helps uh ✌️✌️✌️

he ______ is the depth in the ocean at which calcareous skeletal material first begins to dissolve. Multiple choice question.

Answers

Answer: lysocline

Explanation:

Lysocline is the depth in the ocean at which calcareous skeletal material first begins to dissolve. It is the depth of the ocean whereby the dissolution rate of calcite has a dramatic rise.

Lysocline is also referred to as the transition zone upper bound where the CaCO3 content drops.

explain with example the need of standard measurement system​

Answers

Answer:

A standard system of measurement is very important because it helps us from making mistakes at the moment of doing calculations and correctly working...

Answer:

A standard measurement system is important because it allows scientists to compare data and communicate with each other about their results. Metric System – is a measurement system based on the number 10.

A balloon, inflated in an air-conditioned room at 27.0°C, has a volume
of 4.50.L. It is heated to a temperature of 57.0°C. What is the new
volume of the balloon if the pressure remains constant?

Answers

Answer:

4.95L

Explanation:

Using Charle's law equation;

V1/T1 = V2/T2

Where;

V1 = initial volume (L)

V2 = final volume (L)

T1 = initial temperature (K)

T2 = final temperature (K)

According to the question, the following information was given:

V1 = 4.50L

V2 = ?

T1 = 27°C = 27 + 273 = 300K

T2 = 57°C = 57 + 273 = 330K

Using V1/T1 = V2/T2

4.50/300 = V2/330

Cross multiply

300 × V2 = 4.5 × 330

300V2 = 1485

V2 = 1485 ÷ 300

V2 = 4.95L

1 x 10^-3 m is the same as which of the following? Select all that apply.


a

10000 m

b

1/1000 m

c

1/0.1 m

d

0.001 m

e

100 m

Answers

Answer: b and d

Explanation:

1×10^-3=1×1/10³=1×1/1000=1/1000 so b is correct

1×10^-3=1/1000=0.001

so d is correct

Calculate the numerical Kc value for the following reaction if the equilibrium mixture contains 0.51 M CO , 0.30 M H2 , 1.8 M CH4 , and 2.0 M H2O.

CO(g) + 3H2 (g) ⇌ CH4 (g) + H2O (g)
Show work

Answers

Answer:

uh i think this is the answer

Explanation:

define all the physical features of earth​

Answers

The features discussed are: Plateaus, deserts, deltas, mesas, basins, foothills, marshes, and swamps. Plateaus are elevated regions that are flat on top. Deserts are large areas that receive less than 10 inches of precipitation a year. Antarctica is the world's largest desert.Geography Landforms & Physical Features. Our Earth is made up of a many different types of landforms. ... Mountains. Mountains are large, tall, and elevated land areas on the earth's surface that rise abruptly from the surrounding land area. .

hope it helpsstay safe healthy and happy.....

MOUNTAINS

Mountains are large, tall, and elevated land areas on the earth's surface. They have steep, sloping sides and sharp or rounded ridges, and a high point, called a peak.

PLAINS

Plains are one of the major landforms on earth. They are areas of flat lands.

PLATEAUS

A plateau is a flat, elevated landform that rises above the surrounding area.

DESERTS

Regions of dry, arid lands.

DELTAS

A river delta is a landform created by deposition of sediment that is carried by a river as the flow leaves its mouth and enters slower-moving or stagnant water.

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