Find the no of moles of ca in 8g of ca

How many weeks are equal to 2.94x10^6 minutes?

MAXImum [283]

Answer:

2.94 * (10^6) minutes = 291.666667 weeks

Explanation:

8 0

3 years ago

Cells that identify pathogens and distinguish one from another are called

maks197457 [2]

Lymphocytes, this is the white blood cell that identifies these pathogens

4 0

4 years ago

Analysis of a rock sample shows that it contains 6.25% of its original uranium-235. How old is the rock? How do you know?

nadya68 [22]

Answer:

$2.82\cdot 10^9 y$

Explanation:

A radioactive isotope is an isotope that undergoes nuclear decay, breaking apart into a smaller nucleus and emitting radiation during the process.

The half-life of an isotope is the amount of time it takes for a certain quantity of a radioactive isotope to halve.

For a radioactive isotope, the amount of substance left after a certain time t is:

$m(t)=m_0 (\frac{1}{2})^{\frac{t}{\tau}}$ (1)

where

$m_0$ is the mass of the substance at time t = 0

m(t) is the mass of the substance at time t

$\tau$ is the half-life of the isotope

In this problem, the isotope is uranium-235, which has a half-life of

$\tau=7.04\cdot 10^8 y$

We also know that the amount of uranium left in the rock sample is 6.25% of its original value, this means that

$\frac{m(t)}{m_0}=\frac{6.25}{100}$

Substituting into (1) and solving for t, we can find how much time has passed:

$t=-\tau log_2 (\frac{m(t)}{m_0})=-(7.04\cdot 10^8) log_2 (\frac{6.25}{100})=2.82\cdot 10^9 y$

5 0

4 years ago

Hydrogen gas and aqueous zinc chloride are produced by the reaction of aqueous hydrochloric acid and solid zinc . Write a balanc

Ymorist [56]

1. Write out all the ions/elements and indicate whether they are reactants or products.

Reactants:

Aqueous Hydrochloric Acid: HCl (H has a charge of +1 and Cl has a charge of 1-, so when an ionic bond forms they will form HCl).

Solid Zinc: Zn (since it is a solid zinc with no other forms of elements, the zinc is pure).

Products:

Hydrogen gas: H2 (it has to be H2 because Hydrogen is a diatomic element, and when by itself during reactions, will be H2 instead of H).

Aqueous Zinc Chloride: ZnCl2 (Zn has a charge of 2+ and Cl has a charge of 1-, so through an ionic bond, they will form ZnCl2).

2. Using this information, you can then write out the unbalanced equation.

HCl + Zn -> H2 + ZnCl2

3. Next, indicate their states of matter and any aqueous solutions.

HCl (aq) + Zn (s) -> H2 (g) + ZnCl2 (aq)

4. Try different numbers until you get the same numbers of H, Cl, and Zn on both sides.

2 HCl (aq) + Zn (s) -> H2 (g) + ZnCl2 (aq)

As you can see, the equation contains 2 Hydrogen atoms on both sides, 2 Chloride atoms on both sides, and 1 Zinc atom on both sides. The equation is chemically balanced.

5 0

4 years ago

20 POINTS!!!

nasty-shy [4]

Answer:

300g of water because its a larger amount

Explanation:

3 0

3 years ago

Find the no of moles of ca in 8g of ca​

Find the no of moles of ca in 8g of ca