Which one is a true statement about endothermic reactions?

A waterbed mattress has the following dimensions: 210 cm X 160 cm X 25 cm. The density of water is 62.4lb/ft3. What is the weigh

artcher [175]

Answer: The weight of water bed in pounds is 1850.16 lb

Explanation:

To calculate the volume of cuboid, we use the equation:

$V=lbh$

where,

V = volume of cuboid

l = length of cuboid = 210 cm

b = breadth of cuboid = 160 cm

h = height of cuboid = 25 cm

Putting values in above equation, we get:

$V=210\times 160\times 25=8.4\times 10^5cm^3=29.65ft^3$ (Conversion factor: $1cm^3=3.53\times 10^{-5}ft^3$ )

To calculate the mass of waterbed, we use the equation:

$\text{Density of substance}=\frac{\text{Mass of substance}}{\text{Volume of substance}}$

Density of waterbed = $62.4lb/ft^3$

Volume of waterbed = $29.65ft^3$

Putting values in above equation, we get:

$62.4lb/ft^3=\frac{\text{Mass of waterbed}}{29.65ft^3}\\\\\text{Mass of waterbed}=(62.4lb/ft^3\times 29.65ft^3)=1850.16lb$

Hence, the weight of water bed in pounds is 1850.16 lb

7 0

4 years ago

How would you prepare 250 mL of a 0.100 M solution of fluoride ions from solid CaF2?

andrey2020 [161]

In 250 mL of volumetric flask add 0.975875 grams of $CaF_2$ and dissolve it in the 250 mL of water.

Given:

The solid of calcium fluoride.

To prepare:

The 250 mL solution of 0.100 M of fluoride ions from solid calcium fluoride.

Method:

Molarity of the fluoride ion solution needed = M = 0.100 M

The volume of the fluoride ion solution needed = V = 250 mL

$1 mL = 0.001L\\V=250 mL=250\times 0.001 L=0.250 L$

The moles of fluoride ion needed = n

According to the definition of molarity:

$M=\frac{n}{V}\\0.100M=\frac{n}{0.250 L}\\n=0.100M\times 0.250 L=0.025 mol$

Moles of fluoride ion = 0.025 mol

We know that solid calcium fluoride dissolves in water to give calcium ions and fluoride ions.

$CaF_2(s)\rightarrow Ca^{2+}(aq)+2F^-(aq)$

According to reaction, 2 moles of fluoride ions are obtained from 1 mole of calcium fluoride, then 0.025 moles of fluoride ions will be obtained from:

$=\frac{1}{2}\times 0.025 mol=0.0125 \text{mol of } CaF_2$

Moles of calcium fluoride = 0.0125 mol

Mass of calcium fluoride needed to prepare the solution :

$=0.0125 mol\times 78.07 g/mol=0.975875 g$

Preparation:

Weight 0.975875 grams of calcium fluoride
Add weighed calcium fluoride to a volumetric flask of the labeled volume of 250 mL.
Now add a small amount of water to dissolve the calcium fluoride completely.
After this add more water up to the mark of the volumetric flask of volume 250 mL.

Learn more about molarity of solution ere:

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3 0

3 years ago

What makes a solution a homogeneous mixture? Question 13 options:

Lesechka [4]

The answer is B. uniform in composition.

5 0

3 years ago

Which temperature represents the highest average kinetic energy of the particles in a sample of matter?

AleksandrR [38]

Answer:

41 Which temperature represents the highest average kinetic energy of the particles in a sample of matter? (1) 298 K (3) 27°C (2) 267 K (4) 12°C

Explanation:

highest average kinetic energy highest temperature

5 0

3 years ago

Read 2 more answers

Which property of rubbing alcohol is a chemical property?

matrenka [14]

Chemical formula:C3H8O
Flash point:53°F
Auto ignition temperature:455. 6°C
Solubility:Miscible with water, alcohol, ether, and chloroform
General characteristics:Colorless liquid with slight odor resembling that of rubbing alcohol

8 0

3 years ago