How much water is needed to dissolve 30g or Pb(NO3)2 at 40.0C answer the question? NO BOTS ALLOWED
Answer:
10 must be added
Explanation:
Insects often get stuck in the sap of ancient trees. The sap along with the insect inside harden forming a fossil. What kind of fossil is this?
Cast
Crystallization
Mold
Trace
Which organisms are consumers?
Select all correct answers.
mushrooms
monkey
grasshopper
bacteria
snake
Answer: snake grass hopper and monkey
Explanation: i took the test and this is what i got
Answer:
snake grasshopper and monkey
Explanation:
Haley has been having difficulty breathing. She is having difficulty with the gas exchange in the respiratory system. Which organ is being affected?
Answer:
Lungs.
Explanation:
This is because the lungs are respiratory organs in the body that are located at the either side of the thorax or chest. These are organs that are incharge of exchange of gases. The air is breathe in through the trachea i.e oxygen is inhaled and carbondioxide which is the waste product is exhaled. Gas exchange take place in the lungs.
Define what natural gas is, explain how it forms, and
what it is used for today.
Answer:
is a naturally occurring hydrocarbon gas mixture consisting primarily of methane, but commonly including varying amounts of other higher alkanes, and sometimes a small percentage of carbon dioxide, nitrogen, hydrogen sulfide, or helium.
It is formed when layers of decomposing plant and animal matter are exposed to intense heat and pressure under the surface of the Earth over millions of years. The energy that the plants originally obtained from the sun is stored in the form of chemical bonds in the gas
for heating, cooking, and electricity generation. It is also used as a fuel for vehicles and as a chemical feedstock in the manufacture of plastics and other commercially important organic chemicals.
where does energy come from? newsela
Answer:
All of our energy comes from the sun.
Explanation:
The sun sends out huge amounts of energy through its rays every day. Without the sun, life on earth would not exist, since our planet would be totally frozen.
What charge would an ion have if it had more electrons than protong?
A. It would be neutral, since electrons would be outside the nucleus.
B. It would have a net positive charge.
C. It would have no charge.
D. It would have a net negative charge.
Answer:
D. It would have a net negative charge
Explanation:
In an atom, there are electrons, protons and neutrons collectively called SUBATOMIC PARTICLES. The charge of an atom is determined by the number of electrons and protons in that atom. A neutral or uncharged atom possess the same number of electrons and protons.
The charge can thus be calculated as follows:
Charge of atom = no. of protons - no. of electrons.
Hence, when the number of electrons in an atom is higher than that of the protons, it means that the atom has gained negatively charged electrons, making that atom have a net negative charge. For example, In an atom that contains 10 protons and 11 electrons, the charge of that atom will be (10 - 11) = -1. The net charge of that atom will be -1, which is NEGATIVE.
Which salt is most soluble at 90C?
Explanation:
sodium nitrate is most soluble at 90C.
Solubility is the ability to get dissolved. The salt of sodium is the most soluble salt at 90 degrees.
What is solubility?Solubility is the compound's or substance's ability to get dissolved in the solvent for the formation of the solution. It depends on several factors like hydration energy, temperature, pressure, and lattice energy.
The size of sodium is small, it has less lattice energy compared to the hydration energy and can get readily dissolved as it can create a sphere around other ions to form the solution.
Therefore, sodium salt is the most soluble at 90 degrees celsius.
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What will the nervous system feedback do when the human body's temperature drops just below its normal range? Plssss help
Answer:
Homeostasis
Explanation:
The blood vessels constrict and you start to shiver, that shivering generates heat to warm the body to help to body temperature go back to normal. Homeostasis is the condition of keeping your body at a normal condition.
A flash contains 85.6g of C7H5NO3S (Saccharine) in 2.00 litre of a solution. What is the molarity?
Answer:
0.234 M
Explanation:
C- 12.009 x 7
H- 1.001 x 5
N- 14.006
O- 16 x 3
S- 32.059
___________+
183.133 g/mol
[tex]\frac{1mol}{183.133g} *\frac{85.6g}{2.00L}[/tex] = 0.234 M Cancel out the grams mol/L equals molarity. Lowest significant figure is 3
Which of these statements is true of plant cells?
O They are prokaryotic.
O They have no cell membranes.
They can make their own nutrients.
O They work independently of one another.
When glucose is fermented, ethanol is formed together with ………………….
Answer:
carbon dioxide and oxygen
Durante una determinación de acidez en una muestra contaminada, agregas como indicador fenolftaleina y torno a violeta. ¿Qué sustancia utilizarías para titular NaOH o HCI? Y ¿Por qué?
Answer:
HCl, ya que la sustancia es una base que se debe titular con un ácido.
Explanation:
¡Hola!
En este caso, teniendo en cuenta la descripción inicial de la sustancia, la cual se torna violeta cuando se le agrega la fenolftaleína, es posible inderir que esta sustancia es una base con pH básico. Ahora bien, en torno a la especificación de un proceso de titulación, es claro que dicha base debe ser titulada con un ácido, y este caso, con HCl, ácido chlorhídrico, con el fin the alcanzar el punto de equivalencia.
¡Saludos!
When a substance was dissolved in water, the temperature of the water increased. This process is described as
A.
endothermic with the release of energy
B.
endothermic with the absorption of energy
C.
exothermic with the release of energy
D
exothermic with the absorption of energy
Answer: a,
endothermic with the release of energy
A hydrocarbon substituent is called an
How many grams of solid iron will be produced from 32.1 grams of iron (III) oxide? Hint: Balance the equation first
Answer:
22.45g of Fe will be produced
Explanation:
The balanced reaction is:
Fe₂O₃(s) + 3CO(g) → 2Fe(s) + 3CO₂(g)
Where 1 mole of Iron (III) oxide reacts with 2 moles of Iron
To solve this question we have to find the moles of iron (III) oxide. With these moles and the balanced reaction we can find the moles of iron produced and its mass:
Moles iron (III) oxide -Molar mass: 159.69g/mol-
32.1g Fe₂O₃ * (1mol / 159.69g) = 0.201 moles Fe₂O₃
Moles Iron:
0.201 moles Fe₂O₃ * (2mol Fe / 1mol Fe₂O₃) = 0.402 moles of Fe
Mass Fe -Molar mass: 55.845g/mol-
0.402 moles of Fe * (55.845g/mol) =
22.45g of Fe will be producedwhich of the following is an example of a synthesis reaction
Answer: S+O2> SO2
Explanation:
what are two places that producers can get energy?
Answer:
The Food Chain: The answer has to do with trophic levels. As you probably know, the organisms at the base of the food chain are photosynthetic; plants on land and phytoplankton (algae) in the oceans. These organisms are called the producers, and they get their energy directly from sunlight and inorganic nutrients.
Explanation:
Brainliest?
Nate measured an iron bar. He put the iron bar in the hot sun. When he measured the bar after it had been in the sun, it was slightly longer. Which sentence best describes what happened to the iron atoms after the bar was left in the hot sun?
Consider what happens to an iron bar when left out and exposed to sunlight and why it happens.
Evaluate the statements and select the one that best represents what happens.
Provide your reasoning in the text box provided.
The number of atoms increased.
The size of the atoms increased.
The space between each atom increased.
The air in the spaces between the iron atoms expanded.
Answer:
need dim points back ma boi
Explanation:
i need help in this can someone help
Answer:
the limiting reagent is butane
Explanation:
5C₄H₁₀ + 25O₂ → 20CO₂ + 5H₂0
A teacher reacts 84.0 g of sodium bicarbonate with excess hydrochloric acid. What is the percent yield for sodium chloride if 56.0 g of sodium chloride is produced?
4.20%
8.01%
92.0%
95.8%
95.8% is the percent yield for sodium chloride if 56.0 g of sodium chloride is produced in the reaction.
How we calculate the percentage yield?Percentage yield of any chemical reaction can be calculated as:
% yield = (Experimental yield/Theoretical yield) × 100
Given chemical reaction is:
NaHCO₃ + HCl → NaCl + CO₂ + H₂O
In the question it is given that 56 grams of NaCl is produced by mass. But according to the stoichiometry of the reaction 1 mole of NaCl will be produced whose mass should be 58.44 grams. So, % yield will be:
% yield = (56/58.44) × 100 = 95.8%
Hence, option (d) is correct it means 95.8% is the percent yield.
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PLEASE HELP SOMEONE PLEASEEEE
Answer:
the answer is b
hope this helps you!!
Have a lovely day!
-millie :D
what gives bases their properties?
Methane undergoes combustion. Which products form?
CO2, H2O, and O2
C and H2O
CO2 and H2O
CO2 and H
When methane undergoes combustion the carbon dioxide (CO₂) and water (H₂O) is formed. Therefore, option C is correct.
What do you mean by combustion ?A chemical reaction between two or more substances, usually involving oxygen, that produces heat and light in the form of a flame is called as combustion. The reaction is as follows:
CH4(g) + 2O₂(g) → CO₂(g) + 2H₂O
Methane burns in the presence of enough oxygen to produce carbon dioxide (CO₂) and water (H₂O). When it is burned, it produces a large amount of heat, making it an excellent fuel source.
Thus, option C is correct.
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The characteristics of two unknown intermolecular forces, X and Y, are compared in the table.
Intermolecular Forces
х
Y
Occurs between molecules with instantaneous dipoles Occurs between molecules with permanent dipoles and ions
Which of the following conclusions about the two intermolecular forces is correct?
X represents London dispersion forces, and Y represents ion-dipole forces.
X represents dipole-dipole forces, and Y represents ion-dipole forces.
X represents hydrogen bonding, and Y represents dipole-dipole forces.
X represents London dispersion forces, and Y represents dipole-dipole forces.
Answer:
X represents London dispersion forces, and Y represents ion-dipole forces.
Explanation:
London forces occurs between molecules that are normally non-polar (electrically symmetric). It arises from instantaneous dipoles in molecules. It occurs in all substances.
Permanent dipoles are caused by non-symmetric electron distribution in molecules leading to a permanent dipole in the molecule such as in HCl. Interaction between the permanent dipole in these molecules and an ion is called ion-dipole interaction.
Hence; X represents London dispersion forces, and Y represents ion-dipole forces.
X represents London dispersion forces, and Y represents ion-dipole forces.
London forces:
London forces occurs between molecules that are normally non-polar (electrically symmetric). It arises from instantaneous dipoles in molecules. It occurs in all substances.For example: F₂, I₂Ion-dipole forces:
Permanent dipoles are caused by non-symmetric electron distribution in molecules leading to a permanent dipole in the molecule such as in HCl. Interaction between the permanent dipole in these molecules and an ion is called ion-dipole interaction.For example: sodium ion [tex](Na^+)[/tex]and water molecule[tex](H_2O)[/tex]Hence; X represents London dispersion forces,
and Y represents ion-dipole forces.
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A thermite reaction realeses large amounts of heat and light resulting in the melting of the iron metal
Answer:
1. Fe₂O₃ : Al = 1 : 2
2. Fe₂O₃ : Al₂O₃ = 1 : 1
3. Fe₂O₃ : Fe = 1 : 2
Note: The question is incomplete. The complete question is given below :
A thermite reaction releases large amounts of heat and light, resulting in the melting of the iron metal that forms during the reaction. The balanced chemical equation is given below: Fe₂O₃(s) + 2Al(s) ---> Al₂O₃(s) + 2Fe(l) Determine the correct mole ratios for the following substances, based on this chemical equation.
Explanation:
A thermite reaction is a highly exothermic reaction that occurs between a mixture of powdered aluminium and iron (iii) oxide.
The reaction is a redox reaction which produces aluminium oxide and metallic iron.
The heat given out in the reaction melts the iron formed. It is used to join railway tracks or cracked machine parts. The molten iron runs down between the tracks and welds them together.
The balanced equation of the reaction is given below :
Fe₂O₃(s) + 2Al(s) ---> Al₂O₃(s) + 2Fe(l) + Heat
The mole ratio of the reactant and products are as follows:
1. 1 mole of Iron (iii) oxide and 2 moles of aluminium are combined
Fe₂O₃ : Al = 1 : 2
2. 1 mole of aluminium oxide is produced from 1 mole of iron (iii) oxide
Fe₂O₃ : Al₂O₃ = 1 : 1
3. 2 moles of of iron are produced from 1 mole of iron (iii) oxide
Fe₂O₃ : Fe = 1 : 2
How many atoms of gallium are there in a sample of gallium that has a mass of 1.34g?
Answer:
Explanation:
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PLEASE HELP ASAP A gardener plants a new kind of plant that will attract more helpful insects to his garden. Suddenly, the gardener notices a significant increase in the number of spider webs in the garden. Why has most likely occurred in this situation?
The carrying capacity of the environment has changed.
The limiting factor for spiders has increased in amount.
The carrying capacity of the environment has not changed.
The limiting factor for spiders has decreased in amount.
Answer:
The carrying capacity has changed
Explanation:
By adding in the help bugs, the gardener increased the amount of food available for the predators who eat the help bugs, these are the spiders.
The enviroment for spiders now has more food, and can carry more spiders in it.
BRAINIEST!! how do i balance As+H2=AsH3 step by step will give brainiest only to people who do step by step
Answer:
1. As+H2=AsH3
2. draw a line under the problem with this:
A = 1 | A = 1
H = 2 | H = 3
3. We need everything to be equal (2x3 to get 6 then count the As on the product side to get the 2, then add 2 A on the reactant side):
A = 2 | A = 2
H = 6 | H = 6
4. 2As + 3H2 = 2AsH3
hope this helps
8. A transform boundary, where one tectonic plate slides past another, is likely to result in
which of the following?
A. Frequent earthquakes
B. Rift valley formations
C. Intense weathering
D. Mountain building
9. A rising hot air balloon is acted on by a force pulling it upward and by the force of gravity
Nonton's law of inertia what will happen to the balloon
Answer: A. Frequent earthquakes
Explanation: