Ask question

Ask question

All categories

3 years ago

15

Batteries, like those used in flashlights, are single electrochemical cells, not technically batteries?? true or false??????????

??

1 answer:

dezoksy [38]3 years ago

3 0

The answer is true. Hope this helps.

You might be interested in

A chemist wishing to do an experiment requiring 47Ca2+(half-life = 4.536 days) needs 5.00 g of the nuclide. What mass of 47CaCO

Artyom0805 [142]

Answer: The answer is 6.78 grams.

Explanation: The equation used for solving this type of problems is:

$\frac{N}{N_0}=(\frac{1}{2})^n$

where, $N_0$ is the initial amount of radioactive substance, N is the remaining amount and n is the number of half lives.

Number of half lives is calculated on dividing the given time by the half life.

n = time/half life

Time is given as 48.0 hours and the half life is given as 4.536 days. let's make the units same and for this let's convert the half life from days to hours.

$4.536days(\frac{24hours}{1day})$

= 108.864 hours

So, $n=\frac{48.0}{108.864}$ = 0.441

Since 5.00 g is the required amount when the radioactive substance is delivered to the scientist, it would be the final amount that is N. We need to calculate the initial amount. Let's plug in the values in the equation:

$\frac{5.00}{N_0}=(\frac{1}{2})^0^.^4^4^1$

$\frac{5.00g}{N_0}=0.737$

$N_0=\frac{5.00g}{0.737}$

$N_0$ = 6.78 g

So, 6.78 g of the radioactive substance needs to be ordered.

4 0

4 years ago

A liquid has a volume of 34.6ml and a mass of 46g. what is the density

pychu [463]

Density = mass over volume

Hope this helped :)

6 0

3 years ago

A student dissolves 14.9 g of ammonium chloride (NH4Cl in 250. g of water in a well-insulated open cup. She then observes the te

ololo11 [35]

Answer:

Endothermic

4.433kJ

15.91 kJ / mol

Explanation:

In water, ammonium chloride dissolves thus:

NH₄Cl(s) → NH₄⁺(aq) + Cl⁻(aq)

As the student observed the temperature decreased, the reaction is <em>endothermic </em>because absorbs heat from surroundigns when occurs.

It is possible to find the absorbed heat using coffee cup calorimeter equation:

Q = m×C×ΔT

<em>Where Q is heat, m is mass of solution (250g + 14.9g = 264.9g), C is specific heat of solution (It is possible to assume specific heat of pure water, 4.184J/g°C), and ΔT is change in temperature (20.0°C-16.0°C = 4.0°C)</em>

Replacing:

Q = 264.9g×4.184J/g°C×4.0°C

Q = 4433 J = <em>4.433kJ</em>

<em></em>

As enthalpy is the change in heat per mole of reaction, moles of ammonium chloride that reacted were:

14.9g NH₄Cl × (1mol / 53.491g) = <em>0.2786 moles</em>

As heat produced per 0.2786moles were 4.433kJ, heat per mole of ammonium chloride is:

4.433kJ / 0.2786mol = <em>15.91 kJ / mol</em>

<em />

6 0

3 years ago

Bromothymol blue is an acid-base indicator that changes color around ph 7. adding a small amount of bromothymol blue to a basic

Ede4ka [16]

... in neutralization reactions, for example:

NaOH + HCl = NaCl + H₂O

2KOH + H₂SO₄ = K₂SO₄ + 2H₂O

6 0

4 years ago

Read 2 more answers

Rank the quantities from column A from smallest to largest

Ivan

Idk if this will help but try quizlet

4 0

3 years ago