All categories

4 years ago

HELP ME QUICK

Chemistry

2 answers:

kozerog [31]4 years ago

5 0

The answer is A. Heat is released.

I hope that this helps!

Sophie [7]4 years ago

3 0

Quick answer: Exothermic reactions mean that heat has escaped the system. The answer is A. Heat is released.

You might be interested in

A watt of is a unit of power equivalent to 1 joule per second (1 J/sec). In other words, a 60 watt light bulb consumes 60 joules

Juli2301 [7.4K]

The time the chocolate bar could power the laptop in hours is 0.00233 hrs.

Since 200 Calories of chocolate bar were burned to power the 100 Watt laptop, we need to find the number of joules on energy in 200 calories of chocolate bar.

Knowing that 4.2 Joules = 1 Calorie, then

200 Calories = 200 × 1 calorie = 200 × 4.2 Joules = 840 Joules

Since the power required by the laptop is 100 W = 100 J/s and Power, P = energy/time

so, time = energy/power

So, the time for the laptop to use 840 J of energy from the chocolate bar at a rate or power of 100 W = 100 J/s is

time = 840 J ÷ 100 J/s = 8.4 s

So, the time in hours is 8.4 s ÷ 3600 s/1 h = 0.00233 hrs (since 1 hr = 3600 s)

So, the time the chocolate bar could power the laptop in hours is 0.00233 hrs.

Learn more about time to power here:

brainly.com/question/17732603

7 0

3 years ago

How to write 0.0000658

ohaa [14]

Answer:

0.0000658

Explanation:

6 0

3 years ago

Read 2 more answers

Calculate molecules in 1dm^3 of oxygen

Archy [21]

Number of molecules in 1 dm³ Oxygen = 2.71 x 10²²

<h3>Further explanation</h3>

Conditions at T 0 ° C and P 1 atm are stated by STP (Standard Temperature and Pressure). At STP, Vm is 22.4 liters/mol.

The mole is the number of particles contained in a substance

1 mol = 6.02.10²³

1 dm³ of oxygen = 1 L Oxygen

mol Oxygen :

$\tt \dfrac{1}{22.4}=0.045`mol$

molecules of Oxygen :

n=mol=0.045

No = 6.02.10²³

$\tt N=n\times No\\\\N=0.045\times 6.02\times 10^{23}\\\\N=2.71\times 10^{22}$

5 0

3 years ago

3.) How many grams in 6 moles of H3PO4?

iris [78.8K]

Answer: 587.971086 ≈ 587.97

Explanation: one gram in moles of H3PO4 is 97.995181 so if you just have to multiply it by 6 to get the answer. I could be wrong.

5 0

3 years ago

A sucrose solution is prepared to a final concentration of 0.210 MM . Convert this value into terms of g/Lg/L, molality, and mas

vova2212 [387]

Answer:

1) 71.9 g/L

2) 0.221 m olal

3) 7.05% by mass

Explanation:

Step 1: Data given

Concentration of sucrose = 0.210 M

Molar weight of sucrose = 342.3 g/mol

Density of solution = 1.02 g/mL

Mass of water = 948.1 grams

Step 2: Convert this value into terms of g/L

(0.210 mol/L) * (342.3 g/mol) = 71.9 g/L

Calculate the molality

Step 1: Calculate mass water

Suppose we have a volume of 1.00L

Mass of the solution = 1000 mL * 1.02 g/mL = 1020 g solution

We know that there are 71.9 g of solute in a liter of solution from the first calculation. This means

(1020 grams solution) - (71.9 g solute) = 948.1 g = 0.9481 kg water

Step 2: Calculate molality

Molality = moles sucrose / mass water

(0.210 mol) / (0.9481 kg) = 0.221 mol/kg = 0.221 m olal

Mass %

% MAss = (mass solute / mass solution)*100%

(71.9 g) / (1020 g) *100% = 7.05% by mass

4 0

4 years ago