A student dissolves of sodium hydroxide in of water in a well-insulated open cup. He then observes the temperature of the water rise from to over the course of minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: ()()() You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to the correct number of significant digits. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction.
Is this reaction exothermic, endothermic, or neither?
a. exothermic
b. endothermic
c. neither
Answer: a. exothermic
Explanation:
An Endothermic reaction is a type of chemical reaction in which energy is absorbed from the surrounding. The temperature of the surrounding decreases.
An Exothermic reaction is a type of of chemical reaction in which energy is released into the surrounding. The temperature of the surrounding increases.
When sodium hydroxide is dissolved in water, the temperature of water rise which means the heat has been released during dissolution of sodium hydroxide, thus the reaction is exothermic.
What I know about the Alveoli and Gas exchange
Explanation:
What happens during gas exchange in the alveoli?
These are called alveoli. They inflate when a person inhales and deflate when a person exhales. During gas exchange oxygen moves from the lungs to the bloodstream. At the same time carbon dioxide passes from the blood to the lungs.
What is the role of alveoli in gas exchange?
The alveoli are where the lungs and the blood exchange oxygen and carbon dioxide during the process of breathing in and breathing out. Oxygen breathed in from the air passes through the alveoli and into the blood and travels to the tissues throughout the body.
Hydrogen gas + chlorine gas yields hydrogen chloride
Answer:
[tex]H_{2} + Cl_{2} --> 2HCl[/tex]
Explanation:
Hydrogen and chlorine are both diatomic, which means they occur in molecular pairs as gases. This means you will have two atoms of each on the left in the reactants, so you will need to add a coefficient of 2 to have 2 atoms of each on the right in the products.
i) __________are rigid due to strong (ii)___________ of attraction between the particles
Answer:
Liquid Solids are rigid due to strong glass of attraction between the particles.
Explanation:
Your friend John is having trouble with his compost bin. The material in his compost pile doesn't seem to be decomposing
well. You take a sample of the pole and check for the presence of microorganisms under the microscope You see that there
are indeed microorganisms, however, they don't appear to be growing very fast John says that he regularly mixes his
compost pile to expose it to oxygen What is the most likely explanation for this problem?
The temperature may not be high enough to encourage microorganism growth
Inorganic materials may have been included in the compost pile
The temperature may be too high for microorganisms to tolerate
Inappropriate food waste may have been included in the compost pile
What are the correct coefficients for the following chemical reaction:
Al +
Br2 --> __AlBr3
O 3, 3,2
O 2,3,2
0 2,2,3
O 3,2,2
Answer:
2Al + 3Br2 = 2AlBr3 so the second option is right
I have four questions hope you can help me
Answer:
2+2 kaszkqkq
Explanation:
Problems 307 How many milliliters of a 2.5 M NaCl solution would be needed to prepare each solution? a. 1.5L of a 0.75m solution
Answer:
450 mL
Explanation:
First we calculate how many NaCl moles would there be in 1.5 L of a 0.75 M solution, using the definition of molarity:
Molarity = moles / LitersMoles = Molarity * LitersMoles = 1.5 L * 0.75 M =1.125 molOnce again using the definition of molarity, we now calculate how many liters of a 2.5 M solution would have 1.125 moles:
Liters = 1.125 mol / 2.5 M = 0.45 LFinally we convert 0.45 liters to mL:
0.45 L * 1000 = 450 mLGive a reason for each of the following laboratory practices:
I. KMnO4 solution is not acidified with HNO3 before titration
II.FeSO4 solution is usually prepared fresh when needed
III. Alkali are not stored in glass stoped reagent bottles
Answer:
See explanation
Explanation:
The acid commonly used to acidify KMnO4 is H2SO4. The reason why HNO3 is not used is because HNO3 is itself a strong oxidizing agent. HCl is not used because it can react with KMnO4.
FeSO4 solution is usually prepared fresh when needed because if the solution is prepared and left to stand for sometime, FeSO4 is oxidized to Fe2(SO4)3 by air. Fe III does not give the brown ring test.
Alkali are not stored in glass stopped reagent bottles because very strong alkali can cause the stopper to corrode and fuse to the neck of the bottle making it very difficult to open the reagent bottle.
Why to you do that this app doesn’t tell me anything
which energy transformation took place?
Answer:
C
Explanation:
The battery is chemical energy. When it is used in the flashlight, it produces light and thermal energy
PLZ MARK BRAINLIEST :)
PLEASE HELP! DUE IN 5 MINS SUPER EASY CHEMISTRY!!
Which of the following compounds contain the largest number of atoms?
Answer:
C
Explanation:
Since they all are 2 mols worth, all you have to do is count the number of atoms in each molecule
H2SO4 contains 2 hydrogen 1 sulfur 4 oxygen = 7 atoms
H2S contains 2 hydrogen and 1 sulfur = 3 atoms
H3PO4 contains 3 hydrogens 1 phosphorus 4 oxygens = 8 atoms
HNO3 contains 1 hydrogen 1 nitrogen and 3 oxygens = 5 atoms
You have the right answer.
2.00 L of a gas is collected at 25.0°C and 745.0 mmHg. What is the volume at 760.0 mmHg
and 273K. someone help i only have 2 mins left
Answer:
1.79 L
Explanation:
Step 1: Given data
Initial volume of the gas (V₁): 2.00 LInitial temperature of the gas (T₁): 25.0 °CInitial pressure of the gas (P₁): 745.0 mmHgFinal volume of the gas (V₂): ?Final temperature of the gas (T₂): 273 KFinal pressure of the gas (P₂): 760.0 mmHgStep 2: Convert T₁ to Kelvin
We will use the following expression.
K = °C + 273.15
K = 25.0 °C + 273.15 = 298.2 K
Step 3: Calculate the final volume of the gas
We will use the combined gas law.
P₁ × V₁ / T₁ = P₂ × V₂ / T₂
V₂ = P₁ × V₁ × T₂ / T₁ × P₂
V₂ = 745.0 mmHg × 2.00 L × 273 K / 298.2 K × 760.0 mmHg = 1.79 L
Some students decide to plant their own garden. They want to eat a more plant-based diet For meat, they will buy locally from a butcher. Any remaining scraps will be composted and used as fertilizer for their garden Which part of this plan represents recycling to reduce their waste?
composting scraps
planting a garden
eating a plant-based diet
buying locally
Answer:
composting scraps
recycling is the action or process of converting waste into reusable material.
Identify the products for Ca + H2O(l)
Answer:
i
Explanation:
Answer:
Ca(OH)2 + H2
Explanation:
hope this helps
An aluminum pan and a copper pan have the same mass and are heated to the same temperature. Which will feel hotter?
Answer:
The copper pan!
Explanation:
Copper conducts heat well because its atoms contain only one free valence electrons in the outer shell. Elements with a low number of valence electrons transfer heat the best, and copper has only one. Valence electrons move about freely.
Good luck on your assignment!
Which of these shows the correct hierarchical sequence?
organs cells ▸ tissues ► organ systems
cells ► tissues ► organs organ systems
organ systems tissues › cells organs
tissues cells organs ► organ systems
Answer:
cells -> tissues -> organs -> organ system
Answer:
Cells > tissues > Organs > Organs Systems
Explanation:
tissues are made of a group of cells
a specific organ is made up of a geoup of specific type of tissues
and a group of organs make up the organs system
What happens after coral is bleached?
It dies immediately
It produces peroxides
It is susceptible to starvation
It releases algae into the ocean
Explanation:
The Answer Is
That The Coral Releases Its Colours And Becomes Pale White
Number of atoms of C in 14 moles of C4H10 are:
5.81x10^23
24.09x10^23
84.31x10^23
337.23x10^23
Hhelllp mee faastttt! Pls
how many mols of Ti is 3.15 * 10^23 atoms of Titanium
Answer: There are 0.523 moles of Titanium in [tex]3.15\times 10^{23}[/tex] atoms of Titanium
Explanation:
According to avogadro's law, 1 mole of every substance occupies 22.4 L at STP and contains avogadro's number [tex]6.023\times 10^{23}[/tex] of particles.
To calculate the moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given atoms}}{\text {avogadro's number}}[/tex]
[tex]\text{Number of moles of Titanium}=\frac{3.15\times 10^{23}}{6.023\times 10^{23}}=0.523moles[/tex]
How is sedimentary rocks formed?
Answer:
Sedimentary rocks are formed when sediment is deposited out of air, ice, wind, gravity, or water flows carrying the particles in suspension
Explanation:
What is SVD in chemistry
Answer:
Singular value decomposition (SVD)
Explanation:
If u search go ogle u could find a good definition here is one I found:
"Singular value decomposition (SVD) is a technique commonly used in the analysis of spectroscopic data that both acts as a noise filter and reduces the dimensionality of subsequent least-squares fits." credit: science direct <3
Hope this helps! :) Plz mark brainliest!
How can you use the Periodic Table of Elements to help you find information about specific elements? PLZZZ HELP MEEEEEE!!!!
Answer:
Yuh imma help-........
Fish, amphibians, reptiles, birds, and mammals have similar embryos. They all start with gill slits. Fish and some amphibians grow to have gills. Some amphibians, reptiles, birds, and mammals develop lungs to breathe air
They all start with tails. Fish, some amphibians, reptiles, and birds grow tails. Humans do not keep their tails.
Fish and reptiles develop scales. Amphibians, birds, and humans have skin. Birds have feathers, and humans have hair. With which animal do humans exhibit the most linear relationship?
birds
amphibians
reptiles
fish
Answer:
Birds
Explanation: They are both mammals
Answer:
birds
Explanation:
substances decrease in size on __ (heating/ cooling) and contract.
how many atoms of N are in 5.6g of N?
Answer:
ᵐʸ friend ʰᵉʳᵉ ʲᵘˢᵗⁱⁿ ʰᵉˢ already taken ᵃⁿᵈ hes ᶜʳᵃᶜᵏᵉᵈ ᵃᵗ ᶠᵒʳᵗⁿⁱᵗᵉ my guy Uhhh
Explanation:
On a scale of 1️⃣ to , you’re a 9️⃣. I’m the 1️⃣ you need.
A cylinder, with a piston pressing down with a constant pressure, is filled with 1.90 moles of a gas (n1),
and its volume is 40.0 L (V1). If 0.400 mole of gas leak out, and the pressure and temperature remain the
same, what is the final volume of the gas inside the cylinder?
Answer:
31.58 L
Explanation:
From the question given above, the following data were obtained:
Initial mole (n₁) of gas = 1.90 moles
Initial volume (V₁) = 40 L
Final mole (n₂) = 1.90 – 0.40 = 1.5 moles
Final volume (V₂) =.?
The final volume of the gas can be obtained as follow;
V₁ / n₁ = V₂ / n₂
40 / 1.9 = V₂ / 1.5
Cross multiply
1.9 × V₂ = 40 × 1.5
1.9 × V₂ = 60
Divide both side by 1.9
V₂ = 60 / 1.9
V₂ = 31.58 L
Thus, the final volume of the gas is 31.58 L
Which of these metals will displace Iron from Iron Oxide ?
-Copper
-Magnesium
-Silver
-Tin
Answer:
Magnesium
Explanation:
Magnesium is above iron in the reactivity series, which means that Mg can take oxygen from iron as it is a more reactive metal.
Which describes the polarity in a water molecule?
A. partial negative charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms
B. partial negative charge on the oxygen atom because it pulls electrons from the hydrogen atoms
C. partial positive charge on the oxygen atom because it pulls electrons from the hydrogen atoms
D. partial positive charge on the oxygen atom because its electrons are pulled toward the hydrogen atoms
The answer is B
Answer:
B. partial negative charge on the oxygen atom because it pulls electrons from the hydrogen atoms
Explanation:
Oxygen has a charge of 6 so they need to pull 2 electrons from hydrogen, which creates a partial negative charge.
How many moles of Na are in 42g of Na?
Answer:
n=m/M, so
Explanation:
Molar mass of Na is 22,9... so rounded to 23
n=42g/23g/mol
=1,826mol