All categories

3 years ago

What is the mass of calcium in 2.3•10^23 molecules of calcium phosphate

Chemistry

1 answer:

Katena32 [7]3 years ago

3 0

Explanation:

N(Ca)=3×N(Ca₃(PO₄)₂)=

=3×2.3×10²³=6.9×10²³

6.02×10²³→40g

6.9×10²³→Xg

m(Ca)=X≈45.85g

You might be interested in

Nick hypothesizes that wax has a higher melting point than chocolate how can he test his hypothesis

LUCKY_DIMON [66]

Melt chocolate and measure the temperature and then melt wax and measure the temperature and compare his results.

5 0

4 years ago

The half-life of nitrogen-13 is 10.0 minutes. if you begin with 53.3 mg of this isotope, what mass remains after 25.9 minutes ha

zimovet [89]

Hello!

The half-life is the time of half-disintegration, it is the time in which half of the atoms of an isotope disintegrate.

We have the following data:

mo (initial mass) = 53.3 mg

m (final mass after time T) = ? (in mg)

x (number of periods elapsed) = ?

P (Half-life) = 10.0 minutes

T (Elapsed time for sample reduction) = 25.9 minutes

Let's find the number of periods elapsed (x), let us see:

$T = x*P$

$25.9 = x*10.0$

$25.9 = 10.0\:x$

$10.0\:x = 25.9$

$x = \dfrac{25.9}{10.0}$

$\boxed{x = 2.59}$

Now, let's find the final mass (m) of this isotope after the elapsed time, let's see:

$m = \dfrac{m_o}{2^x}$

$m = \dfrac{53.3}{2^{2.59}}$

$m \approx \dfrac{53.3}{6.021}$

$\boxed{\boxed{m \approx 8.85\:mg}}\end{array}}\qquad\checkmark$

I Hope this helps, greetings ... DexteR! =)

3 0

3 years ago

For each of the following cases, identify the order with respect to the reactant, A. Case (A ----> product)

damaskus [11]

Answer:

The answers to the question are

1. 2nd and above order order

2. 2nd order

3. 1/2 order

4. 1st order

5. 0 order

Explanation:

We have $\frac{N}{N_{0} } = e^{-\lambda t}$

1. For nth order reaction half life $t_{\frac{1}{2} }$ ∝ $\frac{1}{[A_{0} ]^{n-1} }$

Therefore for a 0 order reaction increasing concentration of the reactant there will increase $t_{\frac{1}{2} }$

First order reaction is independent [A₀].

Second order reaction [A₀] decrease, increase.

Similarly for a third order reaction

1. 2nd order

2. 2nd order reaction

3. Order of reaction is 1/2.

4. 1st order reaction.

5. Zero order reaction.

5 0

3 years ago

A mixture of helium, nitrogen and oxygen has a total pressure of 821 mmHg. The partial pressure of helium is 105 mmHg, and the p

skad [1K]

Answer:

Total partial pressure, Pt = 821 mm Hg

Partial pressure of Helium, P1 = 105 mm Hg

Partial pressure of Nitrogen, P2 = 312 mm Hg

Partial pressure of Oxygen, P3 = ? mm Hg

According to Dalton's law of Partial pressures,

Pt = P1 + P2 + P3

So, <u>P3 = 404 mm Hg</u>

4 0

2 years ago

What does every chemical reaction involve?

IgorC [24]

breaking bonds in reactants and forming new bonds in products. Breaking bonds requires energy, and forming bonds releases energy.

7 0

3 years ago

Read 2 more answers