Answer:
21: True
22: False
23: True
24: False
25: False
26: True
27: True
28: False
30: True
Explanation: Hope this is helpful :)
HELPP!!
in reaction 3Fe+2O2=Fe3O4 if I add 20g of Fe to my solution how many moles of Fe3O4 will produce???
Answer:
0.119 moles
Explanation:
molar mass of Fe = 55.845g
to find moles = mass/ molar mass
so moles of Fe = 20/55.845
= 0.358 moles
for the equation you are given
for every three Fe, it produces 1 Fe3O4 , meaning the ratio is 3:1
if you have 0.358 moles of Fe, that means the number of moles of Fe3O4 will equal to one third of that,
thus
moles of Fe3O4 = 1/3 x 0.358 = 0.119
classify matter as elements mixtures and compounds
Answer:
An element contains just one type of atom. A compound contains two or more different atoms joined together. A mixture contains two or more different substances that are only physically joined together, not chemically. A mixture can contain both elements and compounds.
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:
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
Which of the following best explains how minerals get into streams?
A. Rainwater that is high in minerals from the atmosphere falls into the stream.
B. The stream absorbs minerals from the plants growing in and around its banks.
C. Rainwater dissolves minerals out of the rocks and soil along the stream during runoff.
D. When water evaporates from the ocean, it takes minerals with it and redeposits them as rainwater into the stream.
please help me
Answer:
C:Rainwater dissolves minerals out of the rocks and soil along the stream during runoff
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 is a salient factor?
Answer:
technology is a silent factor
Explanation:
learned about it in computer class.
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*
A trait that is helpful to a species will become more common in that
species over time. This is called what.
A. genetic variation
B. transition
C. overproduction
D. selection
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 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 kind of chemical reaction is this?
Answer:
Ethane Combustion Reaction or just Combustion Reaction
Explanation:
Find the volume of 2.40 moles of gas whose temperature is 50.0°C and whose pressure is 2.00 atm.
what is a food chain OR web, and what is it useful for?
Answer:
-
-
Food webs can be used to study bottom-up or top-down control of community structure.
Explanation:
Food chains are important because they show the intricate relationships in ecosystems. They can reveal how each organism depends on someone else for survival. Food chains also display what happens when a problem occurs and a producer or consumer is lost.
-
-
-
-
How do waves form?
Lesson 2.13
Question 4 options:
Ocean waves don't form
Ocean waves form as wind is absent.
Ocean waves form as wind moves across the surface, transferring its energy to the water.
Ocean waves form as salinity increases.
Answer:
It's the 4th one. waves are created by the wind
Answer:
C. Ocean waves form as wind moves across the surface, transferring its energy to the water.
Explanation:
hope this helps! c:
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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Pleade help me! (If you guys unfortunately I am going to report you) Thank you
Answer:
answer 3
Explanation:
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! :)
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.
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:
Anyone help please more & you get extra points
Answer:
qns-4
1-multicellular organism
2-unicellular organism
3-unicellular organism
4-multicellular organism
5-unicellular organism
6-multicellular organism
7-unicellular organism
Can you help me pretty please !!!
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%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
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
Find Jay's instantaneous speed at 35 minutes.
Find jays instantaneous speed at 35 minutes.
(Help would be greatly appreciated) What is the molarity of a solution which contains 22.41 grams of NaCl in 50.0 mL of solution?
1. 0.488M
2. 7.67mol
3. 7.67M
4. 0.000767M
Answer:
7.67
Explanation:
According to molar concentration, the molarity of solution which contains 22.41 grams of NaCl in 50.0 ml of solution is 7.67 M.
What is molar concentration?Molar concentration is defined as a measure by which concentration of chemical substances present in a solution are determined. It is defined in particular reference to solute concentration in a solution . Most commonly used unit for molar concentration is moles/liter.
The molar concentration depends on change in volume of the solution which is mainly due to thermal expansion. Molar concentration is calculated by the formula, molar concentration=mass/ molar mass ×1/volume of solution in liters.
In terms of moles, it's formula is given as molar concentration= number of moles /volume of solution in liters.Substitution of values in the given formula gives, molarity= 22.41/58.44×1/0.05=7.67 M.
Thus, the molarity of solution which contains 22.41 grams of NaCl in 50.0 ml of solution is 7.67 M.
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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)
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:
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