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2 years ago

PLEASE HELP ME!!! i have no idea how to answer these!

Chemistry

1 answer:

I am Lyosha [343]2 years ago

7 0

Answer: Im answering this for points

DONT COME ON MY STUFF SAYING THAT I GOT SCHOOL TO DO JUST LIKE YOU AND YOUR GIVING ME IRRELEVANT ANWSERS JUST TO GET POINTS? THATS A WASTE OF MY TIME

Explanation:

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2. When a chemical reaction occurs, we often get a combination of

Zanzabum

Answer:

a combination of two or more elements called a compound

4 0

3 years ago

A description of property that uses distances and directions based on monuments, such as a tree or a rock, is called:

Natasha_Volkova [10]

Answer:

Metes and bounds

Explanation:

Metes and bounds -

It refers to the process used to define any land or property , is referred to as metes and bounds .

In this method it includes , torrens , lot and block , rectangular .

The factors like direction and distance depending on the rocks or trees , is used in this method .

Hence , from the given information of the question ,

The correct term is metes and bounds .

6 0

3 years ago

How much energy is required to change the temperature of 35.0 g of Lead

Nezavi [6.7K]

Answer:

Q = 270 Joules (2 sig. figs. as based on temperature change.)

Explanation:

Heat Transfer Equation of pure condensed phase substance => Q = mcΔT

Mixed phase (s ⇄ l melting/freezing, or l ⇄ g boiling/condensation) heat transfer equation => Q = m∙ΔHₓ; ΔHₓ = phase transition constant

Since this is a pure condensed phase (or, single phase) form of lead (Pb°(s)) and not melting/freezing or boiling/condensation, one should use

Q = m·c·ΔT

m = mass of lead = 35.0g

c = specific heat of lead = 0.16J/g°C

ΔT = Temp change = 74°C - 25°C = 49°C

Q = (35.0g)(0.16J/g·°C )(49°C) = 274.4 Joules ≅ 270 Joules (2 sig. figs. as based on temperature change.)

7 0

3 years ago

An archaeologist discovered some charcoal at an excavation site. He sent the samples to a lab for C-14 dating, knowing that the

klio [65]

Here we assume that disintegration has occur so the normal t½ formular will not be used
mathematically we..⅛×5600 =700
therefore it is about 700years option A

7 0

3 years ago

112 g of aluminum carbide react with 174 g water to produce methane and aluminum hydroxide in the reaction shown below.

dolphi86 [110]

<u>Answer:</u> 4.999 moles of excess reactant will be left over.

<u>Explanation:</u>

Limiting reagent is defined as the reagent which is completely consumed in the reaction and limits the formation of the product.

Excess reagent is defined as the reagent which is left behind after the completion of the reaction.

The number of moles is defined as the ratio of the mass of a substance to its molar mass.

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$ .....(1)

Given mass of aluminium carbide = 112 g

Molar mass of aluminium carbide = 143.96 g/mol

Putting values in equation 1:

$\text{Moles of aluminium carbide}=\frac{112g}{143.96g/mol}=0.778mol$

For the given chemical reaction:

$2Al_4C_3(s)+12H_2O(l)\rightarrow 3CH_4(g)+4Al(OH)_3(s)$

By the stoichiometry of the reaction:

2 moles of aluminium carbide reacts with 12 moles of water

So, 0.778 moles of aluminium carbide will react with = $\frac{12}{2}\times 0.778=4.668 mol$ of water

Given mass of water = 174 g

Molar mass of water = 18 g/mol

Putting values in equation 1:

$\text{Moles of water}=\frac{174g}{18g/mol}=9.667mol$

Moles of excess reactant (water) left = 9.667 - 4.668 = 4.999 moles

Hence, 4.999 moles of excess reactant will be left over.

8 0

2 years ago