name two reactions which are endothermic in nature..

Answers

Answer 1

Melting ice cubes. Melting solid salts. Evaporating liquid water

Answer 2

Answer:

ham nahi jante hai be happy


Related Questions

which rock is the result of changes on the Earth's surface?

igneous rock
sedimentary rock
metamorphic rock

Answers

Answer:

metamorphic

Explanation:

when one rock changes another rock the rock that got changed is now metamorphic

define the following terms

A) chemical family


B) period


C) metalloid


Answers

Answer:

Chemical Family means a group of elements in the Periodic Table or, more commonly, compounds that share certain physical and chemical characteristics and have a common name.

A period in the periodic table is a row of chemical elements.

metalloid is an element (e.g. arsenic, antimony, or tin) whose properties are intermediate between those of metals and solid nonmetals or semiconductors.

how many moles of methane are in 7.31*10^25 molecules?

Answers

Answer:

121 mol CH₄

General Formulas and Concepts:

Math

Pre-Algebra

Order of Operations: BPEMDAS

Brackets Parenthesis Exponents Multiplication Division Addition Subtraction Left to Right

Chemistry

Organic

Writing chemical compoundsWriting organic structuresPrefixesAlkanes, Alkenes, Alkynes

Atomic Structure

Using Dimensional AnalysisAvogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.Explanation:

Step 1: Define

7.31 × 10²⁵ molecules CH₄

Step 2: Identify Conversions

Avogadro's Number

Step 3: Convert

[tex]\displaystyle 7.31 \cdot 10^{25} \ molecules \ CH_4(\frac{1 \ mol \ CH_4}{6.022 \cdot 10^{23} \ molecules \ CH_4} ) = 121.388 \ mol \ CH_4[/tex]

Step 4: Check

Follow sig fig rules and round. We are given 3 sig figs.

121.388 mol CH₄ ≈ 121 mol CH₄

when 45mL of 0.25mol/L sulfuric acid is mixed w/ 25mL of 0.58mol/L Calcium hydroxide, the solution has a?

Answers

Pls pls help I don’t have time HELP ASAP. It also detects if it’s right or wrong. Pls pls help I don’t have time HELP ASAP. It also detects if it’s right or wrong.

Can someone balance these equations?

Answers

This is mind numbing, but I got you.

3NaOH + 1FeCl3 = 1Fe(OH)3 + 3NaCl

3Mg + 2H3(PO)4 = 1Mg(PO4)2 + 3H2

You have about ______ liters of blood in your body.

A. picks up nutrients, water, and waste materials

B. pulmonary circulation

C. the lungs, where it picks up oxygen again

D. capillaries

E. 5

F. systemic circulation

Answers

Answer:

E

Explanation:

None of the above.
I think u typed the wrong question

DUE VERY VERY VERY SOON
What are the rows of elements called on the periodic table?

Answers

Answer:

"The elements are arranged in seven horizontal rows, called periods or series, and 18 vertical columns, called groups."

Explanation:

I GIVE OUT FREE POINTS

The monomers of carbohydrates are called?

Answers

Answer:

monosaccharides

Explanation:

Monomers of carbohydrates are simple sugars and the basic building blocks of carbohydrates, they are also known as monosaccharides and are used by the cells of living things to store and produce energy.

Answer:

"the simple sugars" or Monosaccharides

Explanation:

Monosaccharides are the monomers of carbohydrates they are mostly called or referred to as "the simple sugars" hope this helped have a nice day (:

plz mark brainliest (:

determine the theoretical yield.

aluminum metal reacts with aqueous nickel II sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. in this reaction 108 grams of aluminum were combined with 464 grams of nickel II sulfate to produce 274 grams of aluminum sulfate.

Answers

The question is incomplete, the complete question is;

In this stoichiometry problem, determine the percentage yield:

Excess aluminum metal reacts with aqueous nickel(II) sulfate to produce aqueous aluminum sulfate and nickel as a precipitate. In this reaction 108 g of aluminum were combined with 464 g of nickel(II) sulfate to produce 274 g of aluminum sulfate.

Answer:

80%

Explanation:

The correct equation for this reaction is;

2Al(s) + 3NiSO4(aq) --------> Al2(SO4)3 + 3Ni(s)

We already know that Al is in excess then NiSO4 is the limiting reactant.

Hence, Number of moles in 464 g of NiSO4 = mass/ molar mass

Molar mass of NiSO4 = 155 g/mol

Number of moles = 464g/155g/mol = 2.99 moles

Number of moles of Al2(SO4)3 = mass/molar mass

molar mass = 342 g/mol

So, Number of moles = 274g/342g/mol = 0.8 moles

Given the stoichiometric reaction equation;

3 moles of NiSO4 yields 1 mole of Al2(SO4)3

2.99 moles of NiSO4 yields 2.99 * 1/3 = 1 mole of Al2(SO4)3

percentage yield is given by; actual yield/ theoretical yield * 100/1

actual yield =  0.8 moles of Al2(SO4)3

Theoretical yield = 1 mole of Al2(SO4)3

Hence;

% yield = 0.8/1 * 100 = 80%

what mass of carbon dioxide is produced from combustion of 100.0 grams of propane (C^3H^8)

Answers

Answer:

Mass of CO₂ produced = 299.64 g  

Explanation:

Given data:

Mass of CO₂ produced = ?

Mass of propane (C₃H₈) = 100.0 g

Solution:

Chemical equation:

C₃H₈ + 5O₂     →        3CO₂ + 4H₂O

Number of moles of propane:

Number of moles = mass/molar mass

Number of moles = 100.0 g/  44.1 g/mol

Number of moles = 2.27 mol

Now we will compare the moles of propane and carbon dioxide.

                 C₃H₈          :          CO₂

                    1              :            3

                  2.27          :           3/1×2.27  = 6.81 mol

Mass of CO₂:

Mass = number of moles × molar mass

Mass = 6.81 mol × 44 g/mol

Mass = 299.64 g  


1. What is a chemical reaction

Answers

a process that involves rearrangement of the molecular or ionic structure of a substance, as distinct from a change in physical form or a nuclear reaction.

Answer:

Chemical reaction, a process in which one or more substances, the reactants, are converted to one or more different substances, the products. ... A chemical reaction rearranges the constituent atoms of the reactants to create different substances as products

Explanation:

If the length, width, and height of a box are 9.50 cm, 6.75 cm and 3.50 cm, respectively, what is the volume of the box in units of milliliters and liters?

(a) How many mL will the box contain?

(b) How many L will the box contain?

Answers

Answer: 1cm³= 1mL

Explanation:

State and explain each law of motion.

Answers

Answer:In the first law, an object will not change its motion unless a force acts on it. In the second law, the force on an object is equal to its mass times its acceleration. In the third law, when two objects interact, they apply forces to each other of equal magnitude and opposite direction

Explanation:

Answer:

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Explanation:

e

What is period? A group?

Answers

wdym exactly? like a punctuation mark orrrr
A period is for girls and a group is where you hang out with ppl

What happens to water when it freezes?

its mass increases
its mass decreases
its density increases
its density decreases

Answers

Explanation:

When an object undergoes a physical change (solid to liquid, decrease in temperature etc.), the mass of the object remains constant.

When water freezes, the water molecules vibrate closer to one another and there is less space between the molecules.

The same number of water molecules now occupy a smaller volume, therefore their density increases.

The correct answer is the 3rd option.

At the time when the water should be freezed so here the density should be decreased.

What is density?

The density refers to the mass of the unit volume with respect to the material substance.

The formula for density should be d = M/v

So here d means the density

And, m means mass

V means the volume

So it should be expressed in units with respect to the units of grams per cubic centimeter.

Hence the last option is correct.

Learn more about water here: https://brainly.com/question/24720645

Which of the following is an example of a precipitate?
A: liquid evaporating into gas
B: a solid formed from a frozen liquid
C: a chunky solid formed from two liquids combining
D: a liquid solution that contains two substances

Answers

I think should be d. Please give me brainlest let me know if its correct or not okay thanks bye

When something heats up it moves faster when something close down it moves slower

Answers

Answer:

Yes

Explanation:

Answer:

THATS WHAT SHE SAID

Explanation:

What does the formula of an ionic compound tell you?

Answers

Answer:

The overall ionic formula for a compound must be electrically neutral, meaning it has no charge. When writing the formula for the ionic compound, the cation comes first, followed by the anion, both with numeric subscripts to indicate the number of atoms of each.

Explanation:

an object moving with a speed of 5m/s has a kinetic energy of 100J what is the mass of the object

Answers

Answer:

k. e. = 1/2 mv^2

100 = 1/2 * m * 5^2

100 = 1/2 * m * 25

m = 100 *2/25

m = 8 kg

hope it helps you

Please actually help me.
Thank you!

Answers

Answer:

I say 20 is ur best option

Which of the following correctly lists the levels of organization from most complex to least complex? *

Community, Organism, Population, Ecosystem
Ecosystem, Community, Population, Organism
Population, Community, Ecosystem, Organism
Organism, Population, Community, Ecosystem

Answers

Answer:

The last option.

Explanation:

You can immediately eliminate the other options as an organism is clearly the least complex. Only one option begins w/ 'organism'.

Answer:

Its def A, if this helped subscribe to amiredagoat Yt

Explanation:

HELPPP NOW PLSSS IM GIVING 22 POINTS TO WHOEVER ANSWERS
Which is the control center for the endocrine system?

the thymus
the hypothalamus
the pancreas
the thyroid

Answers

Answer:

The hypothalams

Explanation:

It is the part of the brain that controls the endocrine system.

HOPE THIS HELPED

The hypothalams ~~~~~~



A woman has pain in her ovaries. In which
quadrants of her abdominopelvic cavity might she
be experiencing pain?
Check all that apply.
the right lower quadrant
the left lower quadrant
the left upper quadrant
the right upper

Answers

Answer:

The right lower quadrant

The left lower quadrant

Explanation:

Those quadrants contain the ovaries and I just got it correct on the assignment.


5. CaCO, - CaO+CO,
Reaction Type

Answers

Answer:

(a) Decomposition: A substance breaks down to smaller species. [e.g. CaCO3(s) → CaO(s) + CO2(g) Decomposition of limestone to calcium oxide (quicklime) and carbon dioxide on heating.]

CARDS
In a science experiment, Marisa concludes that no chemical reaction has occurred. What evidence would support
this conclusion?

A. the mass and total number of atoms were conserved
B. no energy were released
C. a new element was created
D. no new substance was formed

Answers

Answer:d

Explanation:

Look at the picture. If one of the lightbulbs breaks or is removed, what will happen to the other lightbulb?

2 bulbs and a battery in a single loop of wire.

Question 2 options:

It will stay on


It will go off


It will change colors


It will burn out

HERES ANOTHER FOR YOU GUYS! :)

Answers

Answer:

It will go off.

Explanation:

Since the two bulbs are connected in series with the battery, when one bulb breaks breaks the circuit hence flow of current is stopped from moving to the other bulb

4. Pb +FeSO, - PbSO, +Fe
Reaction Type:



Answers

Answer:Fe

Explanation:

Convert 4.5 x 10-3 to standard Notation
Posted today at 6:30 am
1
=

Answers

Answer:

0.0045

Explanation:

Scientific notation is the way to express the large value in short form.

The number in scientific notation have two parts.

The digits (decimal point will place after first digit)

× 10 ( the power which put the decimal point where it should be)

for example 4.5×10⁻³

In standard notation

4.5 / 10³

0.0045

The expanded notation is standard notation of writing the numerical values which is normal way. The numbers are written as they are, without the power of 10.

Create a creature the reproduces asexually

Answers

Answer:

Hydra bud

Explanation:

this plant reproduces asexually

Dinitrogen pentoxide is used in the preparation of explosives. If 7.93 mol of
dinitrogen pentoxide undergoes simple decomposition, what volume of Oz(9) is
produced at 48.0 °C and 125 kPa?

Answers

The volume of O₂ produced: 84.6 L

Further explanation

Given

7.93 mol of  dinitrogen pentoxide

T = 48 + 273 = 321 K

P = 125 kPa = 1,23365 atm

Required

Volume of O₂

Solution

Decomposition reaction of dinitrogen pentoxide

2N₂O₅(g)→4NO₂(g)+O₂ (g)

From the equation, mol ratio N₂O₅ : O₂ = 2 : 1, so mol O₂ :

= 0.5 x mol N₂O₅

= 0.5 x 7.93

= 3.965 moles

The volume of O₂ :

[tex]\tt V=\dfrac{nRT}{P}\\\\V=\dfrac{3.965\times 0.082\times 321}{1.23365}\\\\V=84.6~L[/tex]

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