1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
stira [4]
3 years ago
12

What is something Kierra can do to get more accurate data on her lettuce plants?

Chemistry
1 answer:
AveGali [126]3 years ago
6 0

Answer:

B

Explanation:

Planting several seeds from each brand being tested is a way of repeating the test to gain better results.

You might be interested in
How many atoms are in each of the following
klio [65]
Okay... what are the following
8 0
3 years ago
Read 2 more answers
How to draw Hess' Cycle for this question ?
NISA [10]

Answer : The standard enthalpy of formation of ethylene is, 51.8 kJ/mole

Explanation :

According to Hess’s law of constant heat summation, the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The formation reaction of C_2H_4 will be,

2C(s)+2H_2(g)\rightarrow C_2H_4(g)    \Delta H_{formation}=?

The intermediate balanced chemical reaction will be,

(1) C_2H_4(g)+3O_2(g)\rightarrow 2CO_2(g)+2H_2O(l)     \Delta H_1=-1411kJ/mole

(2) C(s)+O_2(g)\rightarrow CO_2(g)    \Delta H_2=-393.7kJ/mole

(3) H_2(g)+\frac{1}{2}O_2(g)\rightarrow H_2O(l)    \Delta H_3=-285.9kJ/mole

Now we will reverse the reaction 1, multiply reaction 2 and 3 by 2 then adding all the equations, we get :

(1) 2CO_2(g)+2H_2O(l)\rightarrow C_2H_4(g)+3O_2(g)     \Delta H_1=+1411kJ/mole

(2) 2C(s)+2O_2(g)\rightarrow 2CO_2(g)    \Delta H_2=2\times (-393.7kJ/mole)=-787.4kJ/mole

(3) 2H_2(g)+2O_2(g)\rightarrow 2H_2O(l)    \Delta H_3=2\times (-285.9kJ/mole)=-571.8kJ/mole

The expression for enthalpy of formation of C_2H_4 will be,

\Delta H_{formation}=\Delta H_1+\Delta H_2+\Delta H_3

\Delta H=(+1411kJ/mole)+(-787.4kJ/mole)+(-571.8kJ/mole)

\Delta H=51.8kJ/mole

Therefore, the standard enthalpy of formation of ethylene is, 51.8 kJ/mole

7 0
3 years ago
Yami pours powdered cocoa mix into milk and stirs it. Then she microwaves the mixture for three minutes. When she takes the cup
Katen [24]

Answer:

The correct answer is:

C. Rising steam from the cup of cocoa.

Rising steam from the cup of cocoa is the part of this scenario that convection can be best observed.

Explanation:

3 0
3 years ago
Read 2 more answers
The sodium-potassium exchange pump
trapecia [35]

Answer: The correct answer is option E

Explanation:

Sodium/potassium pump is a mechanism that involves the movement of sodium ions (Na+) out of a cell and potassium ions (K+) into a cell, thereby regulating concentration of ions on both sides of a typical cell membrane.

In this situation, the sodium-potassium pump is usually helps in the establishment of the resting potential. The potassium voltage channels normally closes before the membrane potential is brought to a resting level.

In summary, sodium/potassium pump helps to maintain a balance in the system.

6 0
3 years ago
A 50.0 mL sample of an aqueous H2SO4 solution is titrated with a 0.375 M NaOH solution. The equivalence point is reached with 62
vesna_86 [32]

Answer: The concentration of H_2SO_4 is 0.234 M

Explanation:

According to the neutralization law,

n_1M_1V_1=n_2M_2V_2

where,

n_1 = basicity H_2SO_4 = 2

M_1 = molarity of H_2SO_4 solution = ?

V_1 = volume of  H_2SO_4 solution = 50.0 ml

n_2 = acidity of NaOH = 1

M_1 = molarity of NaOH solution = 0.375 M

V_1 = volume of  NaOH solution = 62.5 ml

Putting in the values we get:

2\times M_1\times 50.0=1\times 0.375\times 62.5

M_1=0.234M

Therefore concentration of H_2SO_4 is 0.234 M

6 0
3 years ago
Other questions:
  • Plz help will give brainliest, 50 pts!!! use your knowledge of the law of conversation of mass to answer the following question:
    11·1 answer
  • Calculate the terminal velocity of a droplet (radius =R, density=\rho_d) when its settling in a stagnant fluid (density=\rho_f).
    8·1 answer
  • To increase a gas ' average kinetic energy must do what?
    14·1 answer
  • What is the symbol for resistance?
    13·1 answer
  • The phase of matter can be changed by:
    10·2 answers
  • Bromination occurs on alkene functional groups, but not on alkenes found within aromatic functional groups, such as the phenyl r
    12·1 answer
  • (a) The first step in ozone formation in the upper atmosphere occurs when oxygen molecules absorb UV radiation of wavelengths ≤
    5·1 answer
  • If H2O is removed from this reaction, what will happen? 2H2 + O2 + 2H20 O A. The product-favored reaction will stop. B. The reac
    7·1 answer
  • How many protons will there be if the atom has 3 electrons and a mass of 7 amu
    8·1 answer
  • Which of the following can’t replace hydrogen of acid in the chemical reaction​
    15·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!