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3 years ago

A block of wood has the mass of 180 grams.it is 10 cm long,6 cm wide and 4 cm thick.what is it’s density?

Chemistry

1 answer:

DochEvi [55]3 years ago

4 0

Answer:

0.75 g/cm³

Explanation:

Given data:

Mass of wooden block = 180 g

Length of block = 10 cm

Width of block = 6 cm

Height or thickness = 4 cm

Density of block = ?

Solution:

Volume of block = height × length × width

Volume of block = 4 cm × 10 cm× 6 cm

Volume of block = 240 cm³

Density of block:

density = mass/ volume

d = 180 g/ 240 cm³

d = 0.75 g/cm³

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Answer: do

Explanation:

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2 years ago

Given that Kp = 3.5 x 10-4 for the reaction 2 CO(g) <=> C(graphite) + CO2(g), what is the partial pressure of CO2(g) at eq

spin [16.1K]

Answer: The partial pressure of carbon dioxide at equilibrium is 0.0056 atm

Explanation:

The given chemical equation follows:

$2CO(g)\rightleftharpoons C\text{ (graphite)}+CO_2(g)$

Initial: 4.00

At eqllm: 4.00-2x x x

The expression of $K_p$ for above reaction follows:

$K_p=\frac{p_{CO_2}}{(p_{CO})^2}$

The partial pressure of pure solids and liquids are taken as 1 in the equilibrium constant expression.

We are given:

$K_p=3.5\times 10^{-4}$

Putting values in above expression, we get:

$3.5\times 10^{-4}=\frac{x}{(4-2x)^2}\\\\x=0.0056,718.28$

Neglecting the value of x = 718.28 because equilibrium pressure cannot be greater than initial pressure

Partial pressure of $CO_2$ = 0.0056 atm

Hence, the partial pressure of carbon dioxide at equilibrium is 0.0056 atm

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3 years ago

5,500 cm scientific notation

Alex73 [517]

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3 years ago

Read 2 more answers

Find the enthalpy of neutralization of HCl and NaOH. 87 cm3 of 1.6 mol dm-3 hydrochloric acid was neutralized by 87 cm3 of 1.6 m

Vesna [10]

Answer : The correct option is, (A) -101.37 KJ

Explanation :

First we have to calculate the moles of HCl and NaOH.

$\text{Moles of HCl}=\text{Concentration of HCl}\times \text{Volume of solution}=1.6mole/L\times 0.087L=0.1392mole$

$\text{Moles of NaOH}=\text{Concentration of NaOH}\times \text{Volume of solution}=1.6mole/L\times 0.087L=0.1392mole$

The balanced chemical reaction will be,

$HCl+NaOH\rightarrow NaCl+H_2O$

From the balanced reaction we conclude that,

As, 1 mole of HCl neutralizes by 1 mole of NaOH

So, 0.1392 mole of HCl neutralizes by 0.1392 mole of NaOH

Thus, the number of neutralized moles = 0.1392 mole

Now we have to calculate the mass of water.

As we know that the density of water is 1 g/ml. So, the mass of water will be:

The volume of water = $87ml+87ml=174ml$

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}=1g/ml\times 174ml=174g$

Now we have to calculate the heat absorbed during the reaction.

$q=m\times c\times (T_{final}-T_{initial})$

where,

q = heat absorbed = ?

$c$ = specific heat of water = $4.18J/g^oC$

m = mass of water = 174 g

$T_{final}$ = final temperature of water = 317.4 K

$T_{initial}$ = initial temperature of metal = 298 K

Now put all the given values in the above formula, we get:

$q=174g\times 4.18J/g^oC\times (317.4-298)K$

$q=14110.008J=14.11KJ$

Thus, the heat released during the neutralization = -14.11 KJ

Now we have to calculate the enthalpy of neutralization.

$\Delta H=\frac{q}{n}$

where,

$\Delta H$ = enthalpy of neutralization = ?

q = heat released = -14.11 KJ

n = number of moles used in neutralization = 0.1392 mole

$\Delta H=\frac{-14.11KJ}{0.1392mole}=-101.37KJ/mole$

Therefore, the enthalpy of neutralization is, -101.37 KJ

3 0

3 years ago

What happens to wavelength as wave frequency increases?

KengaRu [80]

Answer:

As a wavelength increases in size, its frequency and energy (E) decrease. From these equations you may realize that as the frequency increases, the wavelength gets shorter. As the frequency decreases, the wavelength gets longer.

Explanation:

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3 years ago