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guajiro [1.7K]
2 years ago
12

Four people make observations recorded in the table.

Chemistry
2 answers:
Sav [38]2 years ago
8 0

Answer:

They involve changes in energy.

Explanation:

hope this helps

plz mark brainliest

77julia77 [94]2 years ago
6 0

Answer:

D. They involve changes in energy.

The last one

Explanation:

have a good day

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Why is a mass movement of mud called a flow?
wariber [46]
In terms of a deeper scientific reason, I am not sure, but the basic reason is quite simple. "Mud" tends to look like a mix between a solid, dirt, and a liquid, water or some other liquid. Since it is, in fact, a cross between a solid and a liquid, it has properties of both. It has certain physical and visual properties that only a solid would have, such as texture and opaqueness, but it also has physical properties of a liquid. Since it leans more towards the liquid side than the solid side, we say mud "flows" rather than saying that it "rolls" or "bounces".
5 0
3 years ago
What is the purpose of a catalyst?
marusya05 [52]

Answer:

option c

Explanation:

as catalyst increases the reaction while activation energy is inversely proportional to rate of reaction, so option c is correct

8 0
3 years ago
How many grams are in 4.5 x 10^22 molecules of Ba(NO2)2
NNADVOKAT [17]

Answer:

17 g Ba(NO₂)₂

General Formulas and Concepts:

<u>Chemistry</u>

  • Stoichiometry
  • Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

Explanation:

<u>Step 1: Define</u>

4.5 × 10²² molecules Ba(NO₂)₂

<u>Step 2: Define conversion</u>

Molar Mass of Ba - 137.33 g/mol

Molar Mass of N - 14.01 g/mol

Molar Mass of O - 16.00 g/mol

Molar Mass of Ba(NO₂)₂ - 137.33 + 2(14.01) + 4(16.00) = 229.35 g/mol

<u>Step 3: Dimensional Analysis</u>

<u />4.5 \cdot 10^{22} \ mc \ Ba(NO_2)_2(\frac{1 \ mol \ Ba(NO_2)_2}{6.022 \cdot 10^{23} \ mc \ Ba(NO_2)_2} )(\frac{229.35 \ g \ Ba(NO_2)_2}{1 \ mol \ Ba(NO_2)_2} )

= 17.1384 g Ba(NO₂)₂

<u>Step 4: Check</u>

<em>We are given 2 sig figs. Follow sig fig rules.</em>

17.1384 g Ba(NO₂)₂ ≈ 17 g Ba(NO₂)₂

7 0
2 years ago
13. When iron nad is put in to a beaker containing copper sulphate solution.
svetlana [45]

Answer:

A simple displacement reaction occurs when an iron nail is immersed to a beaker containing copper sulphate solution.

a)

Iron is more reactive than copper. As a result a displacement reaction will take place. The ferrous or Fe (II) irons will move to the solution. The copper ions (Cu II) will get deposited on the nail. This will cause the colour to change from blue to green.

b)

The equation can be written as:

Fe (s) + CuSO4 (aq) -> FeSO4 (aq) + Cu (s)

c)

A chemical change can be described as a change that causes a substance to change to another form. Hence, this reaction is a chemical change.

4 0
3 years ago
Use stoichiometry to determine how many moles of O2 are needed
STALIN [3.7K]

Answer:

11.25 moles of O₂.

Explanation:

We'll begin by writing the balanced equation for the reaction. This is illustrated below:

C₃H₈ + 5O₂ —> 3CO₂ + 4H₂O

From the balanced equation above,

1 mole of C₃H₈ reacted with 5 moles of O₂.

Finally, we shall determine the number of mole of O₂ needed to react with 2.25 moles of C₃H₈. This can be obtained as follow:

From the balanced equation above,

1 mole of C₃H₈ reacted with 5 moles of O₂.

Therefore, 2.25 moles of C₃H₈ will react with = 2.25 × 5 = 11.25 moles of O₂.

Thus, 11.25 moles of O₂ is needed for the reaction.

7 0
3 years ago
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