The mass of the Pbl2 : 1308.87
Further explanationGiven
18.2 mL of a 0.156 M Pb(NO3)2
26.2 mL of a 0.274 M KI
Reaction
Pb(NO3)2 (aq) + 2 KI (aq) - Pbl2 (s) + 2 KNO3
Required
the mass of the Pbl2
Solution
mol Pb(NO3)2 = 18.2 x 0.156 = 2.8392 mlmol
mol KI = 26.2 x 0.274 =7.1788 mol
Limiting reactant Pb(NO3)2(smaller ratio of mol : reaction coeffiecient)
mol Pbl2 based on limiting reactant (Pb(NO3)2)
From equation, mol ratio of Pb(NO3)2 : Pbl2 = 1 : 1, so mol Pbl2=mol Pb(NO3)2=2.8392
Mass Pb(NO3)2 :
[tex]\tt mass=mol\times MW\\\\mass=2.8392\times 461\\\\mass=1308.87~grams[/tex]
The heat of fusion of a compound is 126 Joules
per gram. What is the total number of Joules of
heat that must be absorbed by a 15.0-gram
sample to change the compound from solid to
liquid at its melting point?
Answer:
1.89 × 10³ J
Explanation:
Step 1: Given data
Heat of fusion (ΔH°fus): 126 J/gMass of the sample (m): 15.0 gStep 2: Calculate the heat (Q) required to melt the sample
The fusion is the phase change from solid to liquid. We can calculate the heat required for the fusion of the sample using the following expression.
Q = ΔH°fus × m
Q = 126 J/g × 15.0 g
Q = 1.89 × 10³ J
When a living organism is successful in meeting all its needs ,this is called
A.active transport
B.endocytosis
C.homeostasis
D.exocytosis
Answer:
homeostasis
Explanation:
source Wiki
In biology, homeostasis (or “health”) is the state of steady internal, physical, and chemical conditions maintained by living systems. This is the condition of optimal functioning for the organism and includes many variables, such as body temperature and fluid balance, being kept within certain pre-set limits (homeostatic range). Other variables include the pH of extracellular fluid, the concentrations of sodium, potassium and calcium ions, as well as that of the blood sugar level, and these need to be regulated despite changes in the environment, diet, or level of activity. Each of these variables is controlled by one or more regulators or homeostatic mechanisms, which together maintain life.
A solution is made by dissolving
14.57 g of sodium bromide (NaBr) in
415 g of water.
What is the molality of the solution?
[?] m NaBr
Molar mass of NaBr: 102.89 g/mol
Answer:
0.342 m
Explanation:
From the question given above, the following data were obtained:
Mass of NaBr = 14.57 g
Mass of water = 415 g
Molar mass of NaBr = 102.89 g/mol
Molality of NaBr =?
Next, we shall determine the number of mole in 14.57 g of NaBr. This can be obtained as follow:
Mass of NaBr = 14.57 g
Molar mass of NaBr = 102.89 g/mol
Mole of NaBr =?
Mole = mass / molar mass
Mole of NaBr = 14.57 / 102.89
Mole of NaBr = 0.142 mole
Next, we shall convert 415 g of water to kg. This can be obtained as follow:
1000 g = 1 Kg
Therefore,
415 g = 415 g × 1 Kg / 1000 g
415 g = 0.415 Kg
Thus, 415 g is equivalent to 0.415 Kg.
Finally, we shall determine Molality of the solution as follow:
Mole of NaBr = 0.142 mole
Mass of water = 0.415 Kg
Molality of NaBr =?
Molality = mole / mass of water in Kg
Molality of NaBr = 0.142 / 0.415
Molality of NaBr = 0.342 m
Therefore, the molality of NaBr solution is 0.342 m.
Answer:
0.341
Explanation:
as stated underneathe the 'tutor verified' answer. lol
How many milliliters of 0.128 M nitric acid are required to neutralize 11.1 mL of 0.184 M sodium hydroxide? Answer with the correct number of significant digits.
Answer:
I think 7.72 mL
11.1/184 × 128/184=7.72
How many protons are in an element with an atomic number of 8 anda mass number of 18?
3
8
10
18
Answer: 8
Explanation:
The atomic number of an element refers to the number of protons that it has in its nucleus. Carbon for instance has an atomic number of 6 because there are 6 protons in its nucleus.
This atomic number will also tell you the number of electrons the element (in its neutral state) has because protons and electrons are the same number. The reason the mass number is 18 in this scenario is that the element has 10 neutrons in its nucleus.
Lithium and nitrogen react in a combination reaction to produce lithium nitride:
6Li(s) + N_2(g) → 2Li_3N(s)
In a particular experiment, 1 00 g samples of each reagent are reacted. The theoretical yield of Iithium nitride is __________.
a. 5.0
b. 0.84
c. 1.01
d. 1.67
e. 2.50
Answer:
Option D. 1.67 g
Explanation:
The balanced equation for the reaction is given below:
6Li (s) + N₂ (g) → 2Li₃N (s)
Next, we shall determine the masses of Li and N₂ that reacted and the mass of
Li₃N produced from the balanced equation. This can be obtained as follow:
Molar mass of Li = 7 g/mol
Mass of Li from the balanced equation = 6 × 7 = 42 g
Molar mass of N₂ = 14 × 2 = 28 g/mol
Mass of N₂ from the balanced equation = 1 × 28 = 28 g
Molar mass of Li₃N = (7×3) + 14 = 21 + 14 = 35 g/mol
Mass of Li₃N from the balanced equation = 2 × 35 = 70 g
SUMMARY:
From the balanced equation above,
42 g of Li reacted with 28 g of N₂ to produce 70 g of Li₃N.
Next, we shall determine the limiting reactant. This can be obtained as illustrated below:
From the balanced equation above,
42 g of Li reacted with 28 g of N₂.
Therefore, 1 g of Li will react with =
(1 × 28)/42 = 0.67 g of N₂
From the calculation made above, we can see that only 0.67 g of N₂ out of 1 g given is required to react completely with 1 g of Li.
Therefore, Li is the limiting reactant and N₂ is the excess reactant.
Finally, we shall determine the theoretical yield of Iithium nitride, Li₃N.
The theoretical yield of Iithium nitride, Li₃N, can be obtained by using the limiting reactant as illustrated below:
From the balanced equation above,
42 g of Li reacted to produce 70 g of Li₃N.
Therefore, 1 g of Li will react to produce = (1 × 70)/42 = 1.67 g of Li₃N.
Thus, the theoretical yield of Iithium nitride, Li₃N is 1.67 g.
A student walks 15 km in 3 hours. What is the student’s average speed?
A :45 km/h
B :5 km/h
12 : km/h
18 : km/h
Answer:
5 km/h
Explanation:
divide the hours to the distance
What mass of carbon monoxide gas (CO) would occupy a volume of 4.30 L at STP? Explain how you got the answer.
Answer:
5.38 g of CO.
Explanation:
From the question given above, the following data were obtained:
Volume of CO = 4.3 L
Mass of CO =?
Next, we shall determine the number of mole of CO that occupied 4.3 L at STP. This can be obtained as follow:
Recall = 1 mole of any gas occupy 22.4 L at STP.
1 mole of CO occupied 22.4 L at STP.
Therefore, Xmol of CO will occupy 4.3 L at STP i.e
Xmol of CO = 4.3 / 22.4
Xmol of CO = 0.192 mole.
Thus, 0.192 mole of CO occupy 4.3 L at STP.
Finally, we shall determine the mass of CO as follow:
Mole of CO = 0.192 mole.
Molar mass of CO = 12 + 16 = 28 g/mol
Mass of CO =?
Mole = mass /Molar mass
0.192 = mass of CO / 28
Cross multiply
Mass of CO = 0.192 × 28
Mass of CO = 5.38 g.
Therefore, 5.38 g of CO occupied 4.3 L at STP.
_______ are white blood cells that recognize specific antigens, and ultimately destroy them.
O lymphocytes
O pathogens
O water
Answer:
Lymphocytes
Explanation:
Pathogens are particles that make you sick like bacteria, viruses, amoebas. Water is essential for life but that's for metabolism, not fighting off against infection or viruses.
Answer:
Lymphocytes
Explanation:
lymphocytes are a kind of white blood cell (WBC). Lymphocytes are cells of the immune system and help fight infection. Lymphocytes live in lymph nodes, but also in the bloodstream and all over the body. Lymphocytes come in two main types: B-cells and T-cells
Where as water is totally not white blood cells and pathogens are viruses and bacterium
Oxidation of a secondary alcohol results in the formation of a(n):________. a) tertiary alcohol b) acid c) aldehyde d) ketone
Answer:
A. Tertiary alcohol
Explanation:
Secondary alcohols are oxidized to ketones - and that's it. For example, if you heat the secondary alcohol propan-2-ol with sodium or potassium dichromate(VI) solution acidified with dilute Sulphuric acid, you get propanone formed. Playing around with the reaction conditions makes no difference whatsoever to the product.
Which of the following is a chemical property?
O volume
O flammability
O color
O weight
Answer:
your answer is flammability
What is Density in chemistry
Answer:
The density of something is the connection between the mass of the substance and how much space it takes up
a.liver e.mouth i.stomach
b.colon f.pancreas
j.large intestine c.gallbladder
g.tongue k.villi d.esophagus
h.peristalsis l.teeth
_8. stores a substance called bile, which physically breaks down fat droplets
_9. Digestion begins when salivary gland secretions enter this
_10. Minute projection extending from the walls of the small intestine and involved in absorbing products of digestion
_11. used to cut, tear, and grind food; adult has 32
_12. when you swallow food, muscular movements carry the food along this structure
to the stomach
13. this organ absorbs excess water form undigested food prior to its release from
the body as a solid waste
_14. Muscular movement involving the walls of the digestive tract that serve to mix materials and move them along the tract
15. it pushes food to the back of the mouth prior to swallowing
_16. this organ produces bile and detoxifies a variety of substances
_17. produces digestive juices that are released into the small intestine
_18. another name for the large intestine
19. functions include mixing food and serving as a reservoir prior to the food being passed on to the small intestine
Answer:
8. c
9. e
10. k
11. L
12. d
13. j
14. h
15. g
16. a
17. F
18. b
19. i
Explanation:
The gallbladder stores a substance called bile, which physically breaks down fat droplets, hence the correct options are 8. C, 9. E, 10. K, 11. L, 12. D, 13. J, 14. H, 15. G, 16. A, 17. F, 18. B, 19. I.
What are the components of the digestive system?Digestion begins when salivary gland secretions enter the mouth. Teeth used to cut, tear, and grind food; adult has 32.
Villi are a minute projection extending from the walls of the small intestine and involved in absorbing products of digestion.
When you swallow food, muscular movements carry the food along the esophagus to the stomach. The large intestine absorbs excess water from undigested food prior to its release from the body as a solid waste.
Muscular movement known as peristalsis involving the walls of the digestive tract that serve to mix materials and move them along the tract.
Therefore, the correct options are 8. C, 9. E, 10. K, 11. L, 12. D, 13. J, 14. H, 15. G, 16. A, 17. F, 18. B, 19. I.
Learn more about digestive system, here:
https://brainly.com/question/23213961
#SPJ2
What happens when Magnesium hydroxide is heated? (Decomposition)
Answer:
It will make magnesium oxide and water
Explanation:
How can you get the sugar out of the sweet tea?
Freeze the water and the sugar will appear as clumps inside the ice.
Just let the sweet to stand and the sugar will settle to the bottom of the glass.
Heat the water Cevaporating iD and you will be left with the sugar.
The answer to the problem: (2.1x103) x (4x105) = _____, written to the correct number of significant digits and in scientific notation is:
!! Carat denotes to the power. Example: 10^4 is 104 !!
Answer: The answer is [tex]8.4\times 10^8[/tex]
Explanation:
Significant figures : The figures in a number which express the value -the magnitude of a quantity to a specific degree of accuracy is known as significant digits.
The rule apply for the multiplication and division is :
The least number of significant figures in any number of the problem determines the number of significant figures in the answer.
Thus for product of [tex](2.1\times 10^3)\times (4\times 10^5)[/tex]
In this problem, 2.1has 2 significant figures and 4 is an exact number with infinite significant digits thus product will have the least number of significant figures which is 2. So, the answer will be in 2 significant figures.
Therefore, the answer is [tex]8.4\times 10^8[/tex]
The waste product of nuclear energy which is a possible pollutant is:
A.smoke
B.hot air
C.radiation
D.heat pollution to lake
Answer:
CCCCCCC
Explanation:
Answer:
C. radiation
Explanation:
the possible pollutant is radiation because nuclear energy causes ; electromagnetic waves are radio waves, light, infrared rays, UV rays, X rays, Gamma rays. These are well known and are used extensively in the fields of communications, industry, medicine and research.
Radiation is a term given for waves caused by electromagnetism and high energy particles .Radioactive substances have High energy particles which are tiny bits of matter that are made to move at high speeds releasing nuclear radiation. There are about 50 naturally occurring radioactive substances and More than 2000 man-made ones. There are three kinds of radioactive radiation – alpha particles, beta particles and gamma radiation.
What is the mass of 0.20 moles of Ga₂(SO₃)₃?
Answer:
75.924 g
Explanation:
To answer this question we first need to calculate the molar mass of Ga₂(SO₃)₃:
Molar Mass of Ga₂(SO₃)₃ = (Molar Mass of Ga)*2 + (Molar Mass of SO₃)*3
Molar Mass of SO₃ = Molar Mass of S + (Molar Mass of O)*3 = 80.06 g/molMolar Mass of Ga₂(SO₃)₃ = (69.72 g/mol)*2 + (80.06 g/mol) * 3
Molar Mass of Ga₂(SO₃)₃ = 379.62 g/molThen we convert 0.20 moles to grams, using the molar mass of Ga₂(SO₃)₃:
0.20 mol Ga₂(SO₃)₃ * 379.62 g/mol = 75.924 gMass of 0.20 moles of Ga₂(SO₃)₃ is 75.924 g
Number of moles:It is defined as the ratio of given mass over molar mass.
Given:
Number of moles= 0.20 moles
To find:
Mass=?
We need to calculate molar mass of Ga₂(SO₃)₃ first:
Molar Mass of Ga₂(SO₃)₃ = (Molar Mass of Ga)*2 + (Molar Mass of SO₃)*3
Molar Mass of SO₃ = Molar Mass of S + (Molar Mass of O)*3 = 80.06 g/mol
Molar Mass of Ga_2(SO_3)_3 = (69.72 g/mol)*2 + (80.06 g/mol) * 3
Molar Mass of Ga₂(SO₃)₃ = 379.62 g/mol
Then we convert 0.20 moles to grams, using the molar mass of Ga₂(SO₃)₃:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}} \\\\\text{Given mass}=\text{Number of moles}*\text{Molar mass}\\\\\text{Given mass}=0.20 moles*379.62 g/mol\\\\\text{Given mass}=75.92 grams\\[/tex]
Thus, the mass of 0.20 moles of Ga₂(SO₃)₃ is 75.92 grams.
Learn more:
brainly.com/question/14464650
A scientist added bacteria and a nutrient medium that could support the growth of the bacteria to a sterilized petri dish. No other materials were added. The graph models the growth of the bacteria over time.
Answer:
A scientist added bacteria and a nutrient medium that could support the growth of the bacteria to a sterilized petri dish. No other materials were added. The graph models growth of the bacteria over time. ... The bacteria did not reproduce in the system, and eventually each individual died at the end of its life cycle.
Explanation:
Plz mark brainliest thanks
Please answer!!! Will give brainliest to best answer!!
1. What is the difference between magma and lava?
2. Under what circumstances do large crystals form from a cooling magma?
3. Under what circumstances do small crystals form from a cooling magma?
4. What happens to the mineral particles in salt water when the water evaporates?
5. Explain how halite forms.
6. Explain how mineral veins form.
Answer:
I can answer 1, lqva is magma outside of the volcano
How many Joules of heat will be given off by 55.0g of water as it cools from 87.3°C to 25.0°C?
Answer:
Q = -14322.77 J
Explanation:
Given data:
Mass of water = 55.0 g
Initial temperature = 87.3°C
Final temperature = 25.0 °C
Heat given off = ?
Solution:
Specific heat capacity:
It is the amount of heat required to raise the temperature of one gram of substance by one degree.
Specific heat capacity of water is 4.18 J/g.°C
Formula:
Q = m.c. ΔT
Q = amount of heat absorbed or released
m = mass of given substance
c = specific heat capacity of substance
ΔT = change in temperature
ΔT = 25.0 °C - 87.3°C
ΔT = - 62.3 °C
Q = 55.0 g×4.18 J/g.°C × - 62.3 °C
Q = -14322.77 J
Describe what happens in the cell before the chemical reaction.
___________________________________________________________
Answer:
Chemical reactions that take place inside living things are called biochemical reactions. The sum of all the biochemical reactions in an organism is referred to as metabolism. Metabolism includes both exothermic (heat-releasing) chemical reactions and endothermic (heat-absorbing) chemical reactions.
___________________________________________________________
PLS HELP ASAP 50 POINTS
The two main factors keep a planet in motion are what and what?
Answer:
Gravity, Inertia, and Velocity ( I decided to use three)
Explanation:
Gravity is the primary force that controls orbit and gravity works with inertia along with velocity.
Gravity, Inertia, and Velocity ( I decided to use three)
Explanation:
Gravity is the primary force that controls orbit and gravity works with inertia along with velocity.
Element X has two known isotopes. If 83% of the sample weighs 76 amu and the remaining 17% weighs 73.6 amu, what is the atomic mass of element X
Answer:
The atomic mass of an element is the average mass of the atoms of an element measured in atomic mass unit (amu, also known as daltons, D). The atomic mass is a weighted average of all of the isotopes of that element, in which the mass of each isotope is multiplied by the abundance of that particular isotope. (Atomic mass is also referred to as atomic weight, but the term "mass" is more accurate.)
Photosynthesis makes (__________) and (____________) for an ecosystem.
Answer:
Oxygen and Sugar (Glucose).
Explanation:
Plants are autotrophs, which means they produce their own food. They use the process of photosynthesis to transform water, sunlight, and carbon dioxide into oxygen, and simple sugars that the plant uses as fuel.
The pH scale for acids and bases ranges from
A. 17
B. 0-14
C. 1-14
D. 1-12
Answer: 0-14
Explanation: Hope this helps
Perform the following
mathematical operation, and
report the answer to the
appropriate number of
significant figures.
15.673 + 14.752 + 8.4568 = [?]
Answer:
38.882
Explanation:
For all those Acellus kids XD
100 points PLEASEEE HELP ASAPPPP PLEASE Identify the kinds of bonds present between/among the given atoms/elements:
Sodium (Na) and Chlorine (Cl) _____________
Oxygen( O) and Oxygen ( O) ______
Sulfur ( S) and Oxygen ( O) ______
Nitrogen (N) and Nitrogen ( N) ________
Aluminum (Al ) and Bromine ( Br) ______
Answer:
20, 50, 25
Explanation:
I just figured it out somehow in my brain.
A sample of water has a mass of 193 g. Salt is added to the water, and the final solution weighs 238 g. How much salt was added? Please help no rush needed but this is due today but no rush..........Thank you so much.
Answer:
45 g of salt was added
Explanation:
238g-193g=45g
How does wood produce chemical energy?
Wood absorbs oxygen to produce chemical energy.
Wood absorbs solar radiation to make chemical energy
Wood absorbs nitrogen gas to make chemical energy.
All living organisms produce unlimited amount of chemical energy.
Answer:
Wood absorbs solar radiation to make chemical energy.
The chemical energy of wood has been absorbed by solar radiation. Thus, option B is correct.
The wood has been the source of energy by the burning for a long duration. The chemical energy has been stored in the dry wood has been converted to light and heat energy on burning.
The energy stored in the wood has been comprised by photosynthesis, where the solar energy has been entrapped in the wood and is converted to chemical energy that is stored.
Thus, the chemical energy of wood has been absorbed by solar radiation. Thus, option B is correct.
For more information about the stored energy of wood, refer to the link:
https://brainly.com/question/20326508