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3 years ago

5

Which of these are examples of physical changes? Check all that apply. burning wood freezing water cutting paper iron rusting mi

xing water and acetone

2 answers:

rodikova [14]3 years ago

5 0

Cutting paper
freezing water
mixing water
acetone

Colt1911 [192]3 years ago

4 0

<u>Answer:</u>

freezing water

cutting paper

mixing water and acetone

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What is the volume of 0.410 moles of co2 at STP

inna [77]

Answer: 9.18 Litres

Standard Temperature and Pressure (STP). Think of this as the perfect environment where the Temp. is 0°C or 273 Kelvin and Pressure is always 1 atm. This is only true in STP.

This question uses the Ideal Gas Equation:

PV=nRT

P= 1 atm

V = ??

T = 273 K (always convert to Kelvin unless told otherwise)

n = 0.410 mol

R = 0.0821 L.atm/mol.K

What R constant to use depends on the units of the other values. (look at the attachments) The units cancel out and only Litres is left. You simply multiply the values.

6 0

3 years ago

Read 2 more answers

Butane (C4H10) is used as a fuel where natural gas is not available. How many grams of butane will fill a 3.50-liter container a

erik [133]

<span>We use the formula PV = nRT. P = 758 torr = 0.997 atm. V = 3.50 L. T = 35.6 C = 308.15 K. R = 0.0821. Rearranging the equation gives up n = PV/Rt and we get .0138 moles of butane. Mass of 0.0138 moles of butane = .0138 x 58.12 = 8.02g.</span>

6 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

The leaves of the rhubarb plant contain high concentrations of diprotic oxalic acid (hooccooh) and must be removed before the st

Andrei [34K]

First we have to find Ka1 and Ka2
pKa1 = - log Ka1 so Ka1 = 0.059
pKa2 = - log Ka2 so Ka2 = 6.46 x 10⁻⁵
Looking at the values of equilibrium constants we can see that the first one is really big compared to second one. so, the pH will be affected mainly by the first ionization of the acid.
Oxalic acid is H₂C₂O₄
H₂C₂O₄ ⇄ H⁺ + HC₂O₄⁻
0.0356 M 0 0
0.0356 - x x x
Ka1 = $\frac{[H^+][HC2O4^-]}{[H2C2O4]}$ = x² / 0.0356 - x
x = 0.025 M
pH = - log [H⁺] = - log (0.025) = 1.6

5 0

2 years ago

Complete the equation C14H30 = ________ + C7H14

Gemiola [76]

Answer:

C14H30 -----> C7H14 + C2H4 +C5H10

Explanation:

3 0

2 years ago