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3 years ago

Somebody please answer this i’ll give brainly

Chemistry

1 answer:

motikmotik3 years ago

4 0

Answer:

number of molecules and the number of moles

Explanation:

Its always same for molcols

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What is the Arrhenius definition of an acid

matrenka [14]

The answer to your question is,

An Arrhenius acid is a type of substance that separates in water to form Hydrogen ions.

-Mabel <3

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3 years ago

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What is the heat of reaction (AH) of the<br> following?<br> C(s) + O2 (g) --> CO2 (g)

zlopas [31]

Answer:

C co2 2co enthalpy

2 Answers. Ernest Z. The standard enthalpy of formation of carbon monoxide is -99 kJ/mol.

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4 years ago

The cost of painting the circular traffic sign shown below is $3.50 per square foot. How much, to the nearest dollar, will it co

KiRa [710]

The cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.

<u>Explanation:</u>

The cost of painting the circular traffic sign is given as 3.50 dollar per square feet. The diameter of the traffic sign is 36 inch, then its radius will be $\frac{36}{2} = 18$ inches.

But as the cost is given in unit of feet, we have to convert the radius from inches to feet.

1 inches = 0.0833 feet

18 inches = 18 × 0.0833 feet

So, the radius of the traffic sign will be approximately equal to 1.5 feet.

The area of the traffic sign will be $\pi r^{2} = 3.14 \times 1.5 \times 1.5 = 7.065$ square feet.

So, if the cost of painting 1 square feet of traffic sign is 3.50 dollar, then

cost of painting 7.065 square feet of traffic sign = 3.50 × 7.065 = 24.7 dollar.

Thus, the cost of painting the traffic sign of 7.065 square feet is approximately equal to 25 dollar.

8 0

3 years ago

Medical cold packs can use various chemicals in order to produce a cold compress to help reduce inflammation caused by injuries.

Illusion [34]

Answer:

Mass of KCL = 218 grams.

Explanation:

Step 1: calculate the heat that must be absorbed(q).

Heat that must be absorbed(q) is calculated as follows:

q= m c (T2-T1).

q = 750g (4.18 J/gC)(20-4 C) = 5.016X10^4 J = 50.16 kJ

Step 2: we determine moles of KCL as follows:

Moles KCl = 50.16 kJ / 17.2 kJ/mol = 2.92 moles.

Step 3: calculate mass of KCL:

Mass of KCl = 2.92 mol X 74.55 g/mol = 218g.

Therefore, 218 grams of KCL would have to be dissolved into 750 g of 20.0°C H2O to produce the solution.

3 0

3 years ago

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A home solar energy storage unit uses 4.75 ✕ 102 L of water for storing energy. On a sunny day, the water absorbed 2.75 ✕ 104 kJ

Sav [38]

Answer : The water's temperature change will be, $13.85^oC$

Explanation : Given,

Density of water = 0.998 g/mL

Volume of water = $4.75\times 10^2L=4.75\times 10^5mL$

(conversion used : 1 L = 1000 mL)

Specific heat of water = $4.184J/g^oC$

Heat absorbed = $2.75\times 10^4kJ=2.75\times 10^7J$

(conversion used : 1 kJ = 1000 J)

First we have to determine the mass of water.

$\text{Mass of water}=\text{Density of water}\times \text{Volume of water}$

$\text{Mass of water}=(0.998g/mL)\times (4.75\times 10^5mL)=474050g$

Now we have to calculate the change in temperature of water.

Formula used :

$Q=m\times C_w\times \Delta T$

where,

Q = heat absorbed by water

m = mass of water

$C_w$ = specific heat of water

$\Delta T$ = change in temperature

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

$2.75\times 10^7J=474050g\times 4.184J/g^oC\times \Delta T$

$\Delta T=13.85^oC$

Therefore, the water's temperature change will be, $13.85^oC$

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3 years ago