Answer:
79'420J
Explanation:
We know mass 250g and
∆T=98°C -22°C
=76°C
The specific heat capacity for water is 4,18Zj/g°C
THEREFORE
∆H=250g•14,8j/g°C •76°C
=79'420J
Oxidation numbers of oxygen in H2PO4 and H2O2 is_____ respectively
Answer:
-2 , -1
Explanation:
H2PO4=-1
+1 × 2 + +5 + 4 ×O=-1
7+ 4O =-1
4O= -8
O = -2
H2O2=0
+1 × 2 +2 x O =0
2 + 2O=0
O= -1
(As the oxidation number of Hydrogen is +1 , and we have 2 hydrogen atoms so we multiply by 2 , while the oxidation number of P is +5 in this equation, also the compound as a whole equals -1 , then we do the steps as followed)
(while the other compound as a whole equals zero , and doing steps as followed)
*if anything is unclear send me a message*
What is the main function of the cell membrane in an animal cell?
Answer:
A cell's plasma membrane, also known as the cell membrane, provides protection. It also maintains a constant atmosphere within the cell, and the membrane serves a variety of purposes. The first is to transport nutrients into the cell, and the second is to transport toxic compounds out
Explanation:
What is a free body diagram? what is it used for?
Answer:
A free body diagram is used to calculate static and dynamic forces acting on an object. In other words, a free body diagram is the starting point to develop a mathematical model to find and calculate various forces acting on a body.
Explanation:
Find the volume of 2.40 moles of gas whose temperature is 50.0°C and whose pressure is 2.00 atm.
How have scientists discovered the structure of atoms?
a.By looking at them under a microscope
b. By running experiments that expose their properties
c. By examining only the largest atoms.
d. Bysplitting them apart.
Answer:
Explanation:Well most scientists used microscopes but they also looked at bigger ones so the answer would be “by running experiments that expose there properties”
If 3.22 g of precipitate are recovered from the reaction of limewater (Ca(OH),) with carbon dioxide to produce
water and calcium carbonate, what is the percent yield if 20.0 g of carbon dioxide was mixed with the
limewater?
the correct answer is 7.1% but i don't understand what they did
Answer:
Percent yield = 7.1%
Explanation:
The general reaction of the problem is:
Ca(OH)₂ + CO₂ → H₂O + CaCO₃
To solve this question we need to find theoretical yield using the amount of carbon dioxide added because:
Percent yield = Actual yield (3.22g) / Theoretical yield * 100
Theoretical yield is the maximum amount of product that could be obtained. To find it we need to convert the mass of CO₂ to moles. The moles of CO₂ = Moles of CaCO₃:
Moles CO₂ -Molar mass: 44.01g/mol):
20.0g * (1mol / 44.01g) = 0.454 moles CO₂ = Moles of CaCO₃ produced
Mass CaCO₃ = Theoretical yield -Molar mass: 100.09g/mol-:
0.454 moles * (100.09g / mol) = 45.5g of CaCO₃ = Theoretical yield.
Replacing:
Percent yield = 3.22g / 45.5g * 100
Percent yield = 7.1%Brainliest to right answer
Find Jay's instantaneous speed at 35 minutes.
Find jays instantaneous speed at 35 minutes.
Sodium carbonate is commonly known as washing soda and is used in detergents as a water softener. What is the molarity of 5.30 g of sodium carbonate, Na₂CO₃, dissolved in 50 L solution?
Answer:
0.1 m
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What results when equal but opposite charges are present in two regions of a polar molecule? A. dipole B. ionic bond C. Electron sea D. crystal lattice
Answer: A. dipole
Explanation:
Dipole can be defined as the separation of the equal and opposite charges present in the molecule via ionic bonding. The water molecule comprising of two molecules of hydrogen being positively charged and one molecule of oxygen being negatively charged are connected via ionic bonding thus water molecule is an example of dipole molecule. There is unequal distribution of the electrical density throughout the molecule.
The polar molecule results in a dipole when equal but opposite charges are present in two regions.
Dipole:
Dipole arises when a molecule have opposite and equal charge in the ends.
For example - water molecule
In water molecule Oxygen is negatively charged and hydrogen have low electronegativity, this difference in electronegativities arise dipole in molecule.
Therefore, the polar molecule results in a dipole when equal but opposite charges are present in two regions.
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What must be happening to the forces of attraction between particles when a change of state occurs?
Answer:
The particles need energy to overcome the attractions between them. As the liquid gets warmer more particles have sufficient energy to escape from the liquid. Eventually even particles in the middle of the liquid form bubbles of gas in the liquid.
What is the definition for floating
Answer:
"1. buoyant or suspended in water or air.
2.not settled in a definite place; fluctuating or variable."
Explanation:
Hope this helps! :)
Eyes, nose, mouth would each be an example of a(n)
a. organ system
b. Cell
c. tissue
d. organ
Answer:
I think it is Organ
Explanation:
PLEASE ASAP! i have c,d,e and f but if anyone can do even one of them please help! (igcse y10 btw)
Answer:
C
i) 2 C(s) + O2(g) → 2 CO
ii) Carbon monoxide poisoning occurs when carbon monoxide builds up in your bloodstream. When too much carbon monoxide is in the air, your body replaces the oxygen in your red blood cells with carbon monoxide. This can lead to serious tissue damage, or even death.
D
The iron oxide gets reduced.
The carbon gets oxidised.
E
the reason is that aluminium is more reactive than carbon to be extracted in a blast furnance.an element lying lower in the metal reactivity series can be reduced by carbon (a reducing agent) but aluminum lies above carbon metal series.
F
i) electrolysis.
ii) It is soft and malleable. Aluminium is used in a huge variety of products including cans, foils, kitchen utensils, window frames, beer kegs and aeroplane parts. This is because of its particular properties.
13. If a chemist has 12.3 moles of N H 03, what is the mass of the sample?
Answer:
209.4831 g
Explanation:
number of moles × molar mass = mass of substance in g
12.3 × ( 14.0067 + 1.00484 × 3 ) = 209.4831 g
what is a salient factor?
Answer:
technology is a silent factor
Explanation:
learned about it in computer class.
Silver is a metal; it reacts with oxygen which is a non-metal to form Silver Oxide. The bond between Silver and Oxygen is called
(Related to Science)
how much energy is used to raise the temperature of 3kg of aluminium from 18°C to 23°C? Use the table below and this equation: Q=mc T
A. 13,455 J
B. 2691 J
C. 13.455
D. 4.485 J
How much energy is required to raise the temperature of 3 kg of aluminum from 18°C to 23°C? Use the table below and this equation: Q=mcΔT
Brainliest to right answer
Seawater is a good source of magnesium. Magnesium is dissolved in the seawater as Mg²⁺. SUGGEST a substance that could be used to precipitate magnesium out of the water. Write a BALANCED CHEMICAL EQUATION and IDENTIFY THE REACTION TYPE to support your thinking
Answer:
SO₄⁻² (aq) + Mg²⁺ (aq) ⇄ MgSO₄ (s) ↓
Precipitation reaction
Explanation:
Mg²⁻ is one of the metals at group 2 in the Perodic Table. This group is called, the alkaline earth metals.
To make precipitate the Mg²⁺ we can use a salt of sulfate, either flouride or phosphate. Those are three salts that can precipitate this metal.
We use sodium as cathion so, first of all we dissociate them:
Na₂SO₄ (aq) → 2Na⁺ (aq) + SO₄⁻² (aq)
NaF (aq) → Na⁺ (aq) + F⁻ (aq)
Na₃PO₄ (aq) → 3Na⁺ (aq) + PO₄⁻³ (aq)
In all cases, the reaction is of the precipitation type and is conditioned by the Kps, the solubility product constant. Let's bond the anions with Mg²⁺.
SO₄⁻² (aq) + Mg²⁺ (aq) ⇄ MgSO₄ (s) ↓ Kps
2F⁻ (aq) + Mg²⁺ (aq) ⇄ MgF₂ (s) ↓ Kps
2PO₄⁻³ (aq) + 3Mg²⁺ (aq) ⇄ Mg₃PO₄ (s) ↓ Kps
Suppose you add water to 6 g of sugar to make a solution with a concentration of 3 g/l What is the total volume of the solution?
Answer:
no
Explanation:
How many moles of NH3 can you make from 6.20 moles of N2?
The term mole concept is used here to determine the moles of ammonia. The number of moles of ammonia which can be make from 6.20 moles of N₂ is 12.4.
What is a mole?One mole of a substance is defined as that quantity of it which contains as many entities as there are atoms exactly in 12 g of carbon - 12. The formula used to calculate the number of moles is:
Number of moles = Given mass / Molar mass
You need one nitrogen atom to produce ammonia. Here we can see that there are two nitrogen atoms in N₂.
One mole of any substance contains Avogadro number of molecules. A mole is defined as the mass of the substance which consists of the equal quantity of basic units.
The number of moles of ammonia from 6.20 moles of N₂ is:
6.20 × 2 = 12.4
Thus the number of moles is 12.4.
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Hi! I need some help with this pleaseeee!!
When two objects of different temperatures are placed in contact with one another, eventually: (choose one option from below)
a) both their average kinetic energy and temperature will be the same
b) their average kinetic energy will be the same
c) neither their average kinetic energy and temperature will be the same
d) their temperature will be the same
2C_H. + 702 — 400, + 6H2O
How many moles of oxygen (O2) are required to produce
45.8 g of water (H20)?
Balanced Eqn
2
C
2
H
6
+
7
O
2
=
4
C
O
2
+
6
H
2
O
By the Balanced eqn
60g ethane requires 7x32= 224g oxygen
here ethane is in excess.oxygen will be fully consumed
hence
300g oxygen will consume
60
⋅
300
224
=
80.36
g
ethane
leaving (270-80.36)= 189.64 g ethane.
By the Balanced eqn
60g ethane produces 4x44 g CO2
hence amount of CO2 produced =
4
⋅
44
⋅
80.36
60
=
235.72
g
and its no. of moles will be
235.72
44
=5.36 where 44 is the molar mass of Carbon dioxide
hope this helps
1What are 2 examples of proteins in the body?
Answer:
1. Insulin
2. Keratin
Explanation:
Proteins are one of the four biological molecules found in living systems. They are polymeric molecules made up of monomeric units called AMINO ACIDS. Proteins perform a wide variety of functions in the body ranging from enzymatic functions to structural roles.
Two examples of proteins found in the body are keratin, insulin. Keratin is a structural protein located in the skin, hair and nails while insulin is an enzymatic protein that aids in digestion.
Can you help me pretty please !!!
what kind of chemical reaction is this?
Answer:
Ethane Combustion Reaction or just Combustion Reaction
Explanation:
The cells of all organisms must produce energy in order for the cell to survive and function. The diagrams below show
different parts of an animal cell and a plant cell.
In which organelle is energy produced in both plant and animal cells?
O Ribosomes
Nucleus
Chloroplast
O Mitochondria
Answer:
Mitochondria Is produced by both animal and plant cells
Explanation:
Pleade help me! (If you guys unfortunately I am going to report you) Thank you
Answer:
answer 3
Explanation:
How can i solve this formula
Answer:
K2 Cr2 O7 is the empirical formula
Explanation:
Assume we have 100 g of the compound, because it makes the number of grams equal to the percentage.
Then convert grams of each element into moles
Then divide the moles of each element by the smallest number of moles attained to get the whole number mole ratios of the empirical formula
However, if you don't get whole numbers when you divide by the smallest number of moles, then multiply all moles by one common factor that makes them all whole numbers.