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
Dovator [93]
2 years ago
15

Help me guys plzlzlz

Chemistry
2 answers:
Kaylis [27]2 years ago
7 0

i think its d because 900+1200 is 2100, but im probably wrong for question 1

mafiozo [28]2 years ago
3 0
The correct answer is d
You might be interested in
Which of the following describes what happens to the atom that was displaced in the reactant compound during a single replacemen
Marysya12 [62]

Answer: It becomes the uncombined element in the product.

Explanation:

The reaction between Zn and HCl is a single displacement reaction according to equation below

Zn + 2HCl —> ZnCl2 + H2

Zn displaces H2 from acid and in the product, hydrogen became the uncombined element.

3 0
3 years ago
Read 2 more answers
What force works against gravity as water infiltrates the soil and moves
love history [14]

Answer:

Answer is option B . This is because water is said to be highly permeable to the underground soil and thus nourishes it , whereas capillary action will make the water flow upward sllowly , but the water is going underground so it is permeability. Also soil is porous too , but that's only if the water is in the soil , here the water is caused to go underground by some force , so porosity isnt the right option

Explanation:

3 0
3 years ago
Read 2 more answers
The pKa of lactic acid is 3.9. A lactate buffer will be useful from pH values ________. The pKa of lactic acid is 3.9. A lactate
Vedmedyk [2.9K]

Answer:

Explanation:

The usefulness of a buffer is its ability to resist changes in pH when small quantities of base or acid are added to it. This ability is the consequence of having both the conjugate base and the weak acid present in solution which will consume the added base or acid.  

This capacity is lost if the ratio of the concentration of conjugate base to the concentration of weak acid differ by an order of magnitude. Since  buffers having ratios differing by more will have their pH driven by either the weak acid or its conjugate base .

From the Henderson-Hasselbach equation we have that

pH = pKa + log [A⁻]/[HA]

thus

0.1 ≤  [A⁻]/[HA] ≤ 10

Therefore the log of this range is -1 to 1, and the pH will have a useful range of within +/- 1 the pKa of the buffer.

Now we are equipped to answer our question:

pH range = 3.9 +/- 1 = 2.9 through 4.9

7 0
3 years ago
A 34.0 g piece of metal is heated to 92.0°C then placed in a beaker of water containing 22.0 g of water at 19.0°C. The temperatu
lapo4ka [179]

Answer:

0.1988 J/g°C

Explanation:

-Qmetal = Qwater

Q = mc∆T

Where;

Q = amount of heat

m = mass of substance

c = specific heat of substance

∆T = change in temperature

Hence;

-{mc∆T} of metal = {mc∆T} of water

From the information provided in this question, For water; m= 22.0g, ∆T = (24°C-19°C), c = 4.18J/g°C.

For metal; m= 34.0g, ∆T = (24°C-92°C), c = ?

Note that, the final temperature of water and the metal = 24°C

-{34 × c × (24°C-92°C)} = 22 × 4.18 × (24°C-19°C)

-{34 × c × (-68°C)} = 459.8

-{34 × c × -68} = 459.8

-{-2312c} = 459.8

+2312c = 459.8

c = 459.8/2312

c = 0.1988

The specific heat capacity of the metal is 0.1988 J/g°C

6 0
2 years ago
2 Points<br> What is the oxidation state of Cl in HCIO3?<br> A:+5 <br> B:-1<br> C:+6 <br> D: -7
Olenka [21]

Answer:

The oxidation state of Cl in HCIO3 is <u><em>+5</em></u>

3 0
2 years ago
Other questions:
  • 49 grams of sulfuric acid, H2SO4, is dissolved in 1 liter of solution. Determine the molarity (M).
    14·1 answer
  • The rate at which energy is transferred is called a power b kinetic energy c work d time
    11·2 answers
  • What will most likely happen in the absence of a vacuole?
    5·1 answer
  • Using the information in the table to the right, calculate the enthalpy of combustion of each of the following substances:
    7·1 answer
  • N2O4(g) 2NO2(g) Which of the following represents the Keq value? 0.18 0.0067 0.131 0.0046
    12·1 answer
  • Blast furnaces extract pure iron from the iron(III) oxide in iron ore in a two step sequence.In the first step, carbon and oxyge
    15·1 answer
  • a solution contains 4.5 times 10 to the negative 3 M HCI. Determine the hydroxide concentreation of the solution.
    9·1 answer
  • Nồng độ mol của 200ml dung dịch Nacl chứa 0,5 mol chất tan là :
    12·2 answers
  • In which or areas on the image dose salinity of the ocean increases
    5·1 answer
  • A student is investigating acceleration using balls with
    13·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!