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3 years ago

What does the number on the top left of the symbol show?

Chemistry

2 answers:

Ad libitum [116K]3 years ago

5 0

Answer: Exponent

Explanation:

For example

2^2 means 2x2

kkurt [141]3 years ago

3 0

Answer:

Atomic mass

Explanation:

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A 3.31-g sample of lead nitrate, Pb(NO3)2, molar mass = 331 g/mol, is heated in an evacuated cylinder with a volume of 2.53 L. T

Dahasolnce [82]

Answer:

0.486atm is the pressure of the cylinder

Explanation:

1 mole of Pb(NO₃)₂ descomposes in 4 moles of NO2 and 1 mole of O2. That is 1 mole descomposes in 5 moles of gas.

To find the pressure of the cylinder, we need to find moles of gas produced, and using general gas law we can determine the pressure of the gas:

Moles Pb(NO₃)₂ and moles of gas:

3.31g * (1mol / 331g) = 0.01 moles of Pb(NO₃)₂.

That means moles of gas produced is 0.05 moles.

Pressure of the gas:

Using PV = nRT

P = nRT/V

Where P is pressure (Incognite)

V is volume (2.53L)

R is gas constant (0.082atmL/molK)

T is absolute temperature (300K)

And n are moles of gas (0.05 moles)

P = 0.05mol*0.082atmL/molK*300K / 2.53L

P = 0.486atm is the pressure of the cylinder

3 0

3 years ago

Process by which plants, algae, and many types of bacteria use sunlight, water, and carbon dioxide to make food and oxygen

Katena32 [7]

Answer: Photosynthesis

Explanation:

The process of photosynthesis is used to help make food for plants. The inputs are sunlight, water (H2O), and carbon dioxide (CO2). Then the outputs are glucose (C6H12O6) which is food, and oxygen (O2) is released.

I hope this helps :)

4 0

2 years ago

What's the Balanced equation for C5H11OH+O2

Galina-37 [17]

The balanced equation is 2 C5H11OH + 15 O2 = 10 CO2 + 12 H2O

8 0

3 years ago

Which substance can not be broken down by a

Tomtit [17]

Answer: (3) silicon

Explanation:

Element is a pure substance which is composed of atoms of similar elements.It can not be decomposed into simpler constituents using chemical reactions.Example: Silicon (Si)

Compound is a pure substance which is made from atoms of different elements combined together in a fixed ratio by mass.It can be decomposed into simpler constituents using chemical reactions. Example: ethane $(C_2H_6)$ , propanone $(CH_3COCH_3)$ and water $(H_2O)$

7 0

3 years ago

What is the molality of a solution of water and kcl if the freezing point of the solution is –3mc030-1.jpgc?

Natasha_Volkova [10]

We will use the expression for freezing point depression ∆Tf
∆Tf = i Kf m
Since we know that the freezing point of water is 0 degree Celsius, temperature change ∆Tf is
∆Tf = 0C - (-3°C) = 3°C
and the van't Hoff Factor i is approximately equal to 2 since one molecule of KCl in aqueous solution will produce one K+ ion and one Cl- ion:
KCl → K+ + Cl-
Therefore, the molality m of the solution can be calculated as
3 = 2 * 1.86 * m
m = 3 / (2 * 1.86)
m = 0.80 molal

4 0

3 years ago