How can you ensure the chemical reaction produces the right amount of heat in a hot pack without hurting you?
Answer:
Heat packs that contain iron and water packets: Exposing the solution to air results in the oxidation of the iron (creates rust). The oxidation of the iron is an exothermic process. Heat packs that contain supersaturated sodium acetate: These are reusable, the packs are boiled to dissolve sodium acetate.
Explanation:Thanks for asking question
Is luster a chemical or physical change? (Worth 50 POINTS!)
Answer:
It is a Physical change, have a great day :)
Explanation:
A chemical change is a permanent change. A Physical change affects only physical properties i.e. shape, size, etc. ... Some examples of physical change are freezing of water, melting of wax, boiling of water, etc. A few examples of chemical change are digestion of food, burning of coal, rusting, etc.
You have a particle of length 68 nm. What is this in meters? ( need help asap)
Answer:
B
Explanation:
Can someone help
Me out pls if your good at chemistry
The compound F2O has two lone pairs on the central oxygen atom. What's the structure of an F2O molecule? Is this compound polar or non-polar? Question 1 options: A) Bent or angular, polar B) Trigonal planar, polar C) Bent or angular, non-polar D) Trigonal planar, non-polar
Answer: A) Bent or angular, polar
Explanation:
The central atom oxygen has two lone pairs and two bond pairs in [tex]OF_2[/tex]. The number of electron pairs are 4, that means the hybridization will be [tex]sp^3[/tex] and the electronic geometry of the molecule will be tetrahedral. But as there are two lone pair of atoms around the central oxygen atom, repulsion between lone and bond pair of electrons is more and hence the molecular geometry will be bent shape.
The compound [tex]OF_2[/tex] is polar as the net dipole moment of oxygen - fluoride bonds do not cancel each other out.
Which section of the ocean floor is near the coastline of all continents?
Answer shallow ocean
Explanation:
i think
- Is energy absorbed or released by a material during the phase change from a solid to a liquid?
A)Absorbed
B)Released
Answer:
A) Abosrbed
Explanation:
The change is endothermic, meaning the material absorbs energy when it changes its phase from a solid to a liqiud.
Volcanic islands can form over hot spots. The Hawaiian Islands started forming over hot spots in the Pacific Ocean millions of years ago. What process causes the hot, solid rock to rise through the mantle at these locations?
Answer: Convection Currents
Explanation:
Due to the different temperature occurring at the upper and lower layers of the mantle, it causes heat transfer to occur. One of such heat transfer is the Convection currents which causes warmer, less dense rock material in the core to rise through the mantle. Also, the cooler rocks in the higher mantle move slowly towards the core.The movement caused by these Convection current in the Earth are called plate tectonics which are responsible for earthquakes and volcanoes.
Sally is building a list of the types of matter that have energy. She includes liquids on her list because she can see that liquids flow. Is her list complete?
a. yes, her list with just liquids on it is complete
b. no, she should add only gases to her list
c. no, she should add only solids to her list
d. no, she should add gases and solids to her list
Answer:
I just looked up the types of matter energy has.
Explanation:
I believe the answer is D.
Sally's list of matter that have energy is not complete as all the types of matter have energy as all matter have mass , and mass and energy are related, so she should have added gases and solids to her list.
What is matter?Matter in chemistry, is defined as any kind of substance that has mass and occupies space that means it has volume .Matter is composed up of atoms which may or not be of the same type.
Atoms are further made up of sub atomic particles which are the protons ,neutrons and the electrons .The matter can exist in various states such as solids, liquids and gases depending on the conditions of temperature and pressure.
The states of matter are inter convertible into each other by changing the parameters of temperature and pressure.
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In an electrically neutral atom of any element, there are equal numbers of
A. Protons and neurons.
B. electrons and procons.
C. electrons and neurrons.
D. atomic number and atomia mess. 5
Answer:
B. electrons and protons.
Explanation:
In an electrically neutral atom of any element, there are equal number of protons and electrons in the atom.
Protons are the positively charged particles in an atom.
Electrons are the negatively charged particles within the atom.
When the number of protons and electrons are the same or equal, the atom is neutral.
But when there is an imbalance, an ion results.
I neeeeeeeeed help you within 30 min
Answer:
The answers to your question are given below
Explanation:
The equation for the reaction is given below:
2KClO₃ —> 2KCl + 3O₂
The total number of each atoms present in the reactants and products can be obtained by doing a head count as illustrated below:
Reactants >>>>>> Number of atoms
Potassium (K) >>> 2 × 1 = 2
Chlorine (Cl) >>>> 2 × 1 = 2
Oxygen (O) >>>>> 2 × 3 = 6
Products >>>>>>> Number of atoms
Potassium (K) >>> 2 × 1 = 2
Chlorine (Cl) >>>> 2 × 1 = 2
Oxygen (O) >>>>> 3 × 2 = 6
A compound whose empirical formula is NO₂ could have a molecular mass of? 23 g/mol 39 g/mol 92 g/mol 120 g/mol
The molecular formula of a compound gives the actual number of atoms of various elements present in one molecule of the compound. The molecular mass is 92 g/mol. The correct option is C.
What is empirical formula?The empirical formula of a compound can be defined as the formula which gives the simplest whole number ratio of atoms of various elements present in one molecule of the compound.
The molecular formula of a compound is a whole number multiple of its empirical formula.
Molecular formula = n × Empirical formula
The value of 'n' can be obtained from the relation:
n = Molecular mass / Empirical formula mass
Here the value of n = 2. Then,
Molecular mass = n × Empirical formula mass
Empirical formula mass of NO₂ = 45.8 g
2 × 45.8 = 91.6 ≈ 92 g/mol
Thus the correct option is C.
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I need help pls Where does it belong to?
3. A property of acids is that they taste sour. A
property of bases is that they feel slippery. Would
you use either of these properties to identify an
unknown substance? Why or why not?
Explanation:
Touching or tasting these unknown substances could be lethal or cause severe burns to your skin, so it is advisable to use other methods to identify substances.
pls answer i need it now!! I will give brainliest to the best answer!!
Answer:
sample 2
Explanation:
hope this helps
PLEASE HELP. WILL GIVE BRAINLIEST AND QUESTION WORTH A 100 POINTS. NEED ANDWER ASAP!
Conclusion: In a paragraph, describe how physical and chemical properties help us
identify the difference between metals, nonmetals and metalloids. Discuss
characteristics that metals have in common, characteristics that nonmetals have in
common, and characteristics that metalloids have in common.
Answer:
extensive properties such as mass and volume depend on something like perhaps the amount of what's measured. physical properties can be measured without changing substance chemical identity.
metals are the elements which exhibit degree of metallic behavior is know as metals. non metals are such elements which do not posses any metallic behavior and mekkloids are those elements that posses some of the properties like metal. but they act either like metals or non metals n they also have the same physical properties
What is an animal-like, unicellular protist called?
protozoan
euglenoid
slime mold
decompos
Answer:
protozoan
Explanation:
An animal - like unicellular protist is called a protozoan. Such organisms shows similarities with animals.
Protozoans are unicellular organisms. They are similar to animals in that they perform nearly all life functions that makes animals very unique. They are mostly heterotrophs which feed on foods that have been produced by autotrophs. Examples are flagellates and ciliates.A sample of methane gas collcted t a pressure of 0.0884 atm and a temperature of 6.00 C is found to occupy a volume of 26.5 L. How many moles of CH4 gas are in the sample? ____ mol
Answer:
0.1mole
Explanation:
Given parameters:
Pressure = 0.0884atm
Temperature = 6°C = 6 + 273 = 279K
Volume occupied = 26.5L
Unknown:
Number of moles = ?
Solution:
To solve this problem, we are going to use the ideal gas equation:
PV = nRT
P is the pressure
V is the volume
n is the number of moles
R is the gas constant = 0.082atmLmol⁻¹k⁻¹
T is the temperature.
Insert the parameters and solve for n;
0.084 x 26.5 = n x 0.082 x 279
n = 0.1mole
what volume (in L) of ethane (C2H6) will be required to produce 42.5 L of carbon dioxide in the reaction below?
2C2H6(g)+7O2(g)->4CO2(g)+6H2O(g)
Answer:
21.25
Explanation:
how many oxygen atoms are in 10.0g of 2Al2 CO3 3
Answer:
0.776 ×10²³ atoms of oxygen
Explanation:
Given data:
Mass of Al₂CO₃ = 10.0 g
Number of atoms of oxygen = ?
Solution:
Number of moles of Al₂CO₃:
Number of moles = mass/molar mass
Number of moles = 10.0 g/233.99 g/mol
Number of moles = 0.043 mol
1 mole of Al₂CO₃ contain 3 mole of oxygen.
0.043 ×3 mol = 0.129 mol
Number of atoms of oxygen:
1 mole contain 6.022×10²³ atoms
0.129 mol × 6.022×10²³ atoms / 1mol
0.776 ×10²³ atoms of oxygen
If you have 8.5 moles of water (H2O), how many grams of water do you have?
Answer: i think it is 144.16
Explanation:
how does the earth give us what we call and night
Answer:
the Earth rotates on an imaginary line called its axis and different parts of the planet are facing towards the Sun or away from it. it takes 24 hours for the world to turn all the way around, and we call this a day.
Explanation:
Stephanie the Skydiver has a mass of 48kg, what is the force that she
exerts as she is falling to the ground?
Answer:
470.4N
Explanation:
Given parameters:
Mass of Stephanie = 48kg
Unknown:
Force she exerts while falling to the ground = ?
Solution:
The force she exerts is her weight;
Weight = mass x acceleration due to gravity
Now insert the parameters ands solve ;
Weight = 48 x 9.8 = 470.4N
A sample of carbon dioxide gas at a pressure of 891 mm Hg and a temperature of 84 C occupies a volume of 5.61 L. If the gas is cooled at constant pressure to a temperature of 40 C, the volume of the gas will be __ L.
Answer:
4.92L
Explanation:
Given parameters:
Initial pressure = 891mmHg
Initial temperature = 84°C = 84 + 273 = 357k
Initial volume = 5.61L
New temperature = 40°C = 273 + 40 = 313k
Unknown:
New volume = ?
Solution:
Since we are dealing with constant pressure condition, we apply charles's law.
It states that the volume of a fixed mass of gas varies directly as its absolute temperature if the pressure is constant.
Mathematically ;
[tex]\frac{V1}{T1}[/tex] = [tex]\frac{V2}{T2}[/tex]
V1 is the initial volume V2 is the new volume
T1 is the initial temperature T2 is the new temperature
[tex]\frac{5.61}{357}[/tex] = [tex]\frac{V2}{313}[/tex]
V2 = 4.92L
Which products would form if chlorine gas was bubbled through a solution of sodium bromide?
a. Na and BrCl
b. Na snd BrCl2
c. Na and Br2
d. Na(cl)2 and Br2
Answer:
NaCl and Br2
Explanation:
Edge 2020
Answer:
The Answer is C: Na and Br3
Explanation:
help me please!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
What are the homologous series?
Explanation:
Homologous series are the series belonging to a series of aliphatic organic compounds that differ only by the addition of a CH2 group
Hope it will help :)❤
How many liters of O2 at STP will react with 8.7 grams of C2H4 to form CO2 and H2O? C2H4 + 3 O2 -------> 2 CO2 + 2 H2O
Answer:
6.944 liters of O₂ at STP will react with 8.7 grams of C₂H₄ to form CO₂ and H₂O.
Explanation:
The balanced reaction is:
C₂H₄ + 3 O₂ ⇒ 2 CO₂ + 2 H₂O
Being the molar mass of the elements:
C: 12 g/moleH: 1 g/moleThen the molar mass of compound C₂H₄ is:
C₂H₄= 2*12 g/mole + 4*1 g/mole= 28 g/mole
By stoichiometry of the reaction (that is, the relationship between the amount of reagents and products in a chemical reaction), 1 mole of C₂H₄ acts. Then, being the mass of a mole of a substance, which can be an element or a compound, 1 mole of C₂H₄ is 28 g, which is the amount of mass that reacts in this case.
Then be able to apply the following rule of three: if by stoichiometry 28 grams of C₂H₄ react with 3 moles of O₂, 8.7 grams of C₂H₄ with how many moles of O₂ do they react?
[tex]moles of O_{2} =\frac{8.7 grams ofC_{2} H_{4}*3 moles of O_{2} }{28grams ofC_{2} H_{4}}[/tex]
moles of O₂= 0.31
The STP conditions refer to the standard temperature and pressure. Pressure values at 1 atmosphere and temperature at 0 ° C are used and are reference values for gases. And in these conditions 1 mole of any gas occupies an approximate volume of 22.4 liters.
Then we can apply the following rule of three: if by definition of STP 1 mole occupies 22.4 L, 0.31 moles how much volume will it occupy?
[tex]volume=\frac{0.31 moles*22.4 L}{1 mole}[/tex]
volume= 6.944 L
6.944 liters of O₂ at STP will react with 8.7 grams of C₂H₄ to form CO₂ and H₂O.
The volume of O₂ at STP that will react with the given C₂H₄ is 20.8 L
First, we will determine the number of moles of O₂ required.
From the given balanced chemical equation,
C₂H₄ + 3O₂ → 2CO₂ + 2H₂O
This means
1 mole of C₂H₄ is required to react completely with 3 moles of O₂
Now, we will determine the number of moles of C₂H₄ present
Mass of C₂H₄ = 8.7 g
Using the formula
[tex]Number\ of\ moles = \frac{Mass}{Molar\ mass}[/tex]
Molar mass of C₂H₄ = 28.05 g/mol
∴ Number of moles of C₂H₄ = [tex]\frac{8.7}{28.05}[/tex]
Number of moles of C₂H₄ = 0.31016 mole
Since
1 mole of C₂H₄ is required to react completely with 3 moles of O₂
Then,
0.31016 mole of C₂H₄ will react completely with 3 × 0.31016 mole of O₂
3 × 0.31016 = 0.9305 mole
∴ Number of moles of O₂ required is 0.9305 mole
Now, for the volume of O₂ at STP that will react
Since 1 mole of a gas occupies 22.4 L at STP
Then,
0.9305 mole of O₂ will occupy 0.9305 × 22.4 L at STP
0.9305 × 22.4 = 20.8432 L
≅ 20.8 L
Hence, the volume of O₂ at STP that will react with the given C₂H₄ is 20.8 L
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Apollo 11 made a ______ landing.
Answer:
Apollo 11 made a capsule landing
Explanation:
Answer: i don’t know what type of landing you mean
Explanation:
They did a lunar landing then reentry and then capsule landing.
I traveled for 0.5 hr at 80 km/h. How far did I travel?
Answer:
[tex]Distance = 40km[/tex]
Explanation:
Given
[tex]Speed = 80km/hr[/tex]
[tex]Time = 0.5hr[/tex]
Required
Determine the distance covered
Distance is calculated as:
[tex]Distance = Speed * Time[/tex]
Substitute values for Speed and Time
[tex]Distance = 80km/hr * 0.5hr[/tex]
[tex]Distance = 80km * 0.5[/tex]
[tex]Distance = 40km[/tex]
Hence, you travelled 40km
