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2 years ago

Which of the following is a true statement?

Chemistry

1 answer:

BlackZzzverrR [31]2 years ago

6 0

Answer:

its either all animals or only mammals. the thing with all animals is that they do have life cycles but not the same as like say humans or elephants, some are complicated.

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Write the number in scientific nation form

Yuri [45]

Answer:

its already in scientific notation form however its ordinary or real form is -0.005682

Explanation:

scientific notation

when a number is expressed with some power of 10 multiplied by a number between 1 to 10 is called scientific notation

4 0

3 years ago

What planet has the highest ambient temperature?

cupoosta [38]

Venus is the hottest planet

4 0

3 years ago

Read 2 more answers

) how much of the primary standard benzoic acid (fm 122.12, density 1.27 g/ml) should you weigh out to obtain a 100.0 mm aqueous

aniked [119]

We must know that molarity is a unit for concentration and it is expressed as:

molarity = moles / liters

The molarity is 100 millimolar, or 0.1 molar. The volume is 250 ml, or 0.25 liters. Using the formula above, we find the moles of benzoic acid required.

moles = molarity * liters
moles = 0.1 * 0.25
moles = 0.025

Next, we know that the molar mass for benzoic acid is 122.12 g/mol and the moles of a substance are given by:
moles = mass / molar mass

mass = moles * molar mass
mass = 0.025 * 122.12
mass = 3.05 grams

You will need to weigh out 3.05 grams of benzoic acid

8 0

3 years ago

The identity of an element depends on the number of protons and neutrons in the nucleus. protons in the atom. neutrons in the at

labwork [276]

Answer:

protons in the atom.

Explanation:

The identity of an element relies on the number of protons in its atom. This is called the atomic number. The atomic number is the basis of the periodic table of elements. Modern periodic law states that "the properties of elements are a periodic function of their atomic number".

Atomic number of atoms do not change and they are convieniently used in identifying an atom.

8 0

3 years ago

What is the pOH of a<br> 2.6 x 10-6 M H+ solution?

melomori [17]

Answer:

Approximately $8.41$ (assuming that the solution is at $\rm 25^\circ C$ , under which $K_{\rm w} = 10^{-14}$ .)

Explanation:

Let ${\rm [H^{+}]}$ and ${\rm [OH^{-}]}$ denote the concentration of $\rm H^{+}$ and $\rm OH^{-}$ respectively.

Let $K_{\rm w}$ denote the self-ionization constant of water. The exact value of $K_{\rm w}\!$ depends on the temperature of the solution. $K_{\rm w} =10^{-14}$ at $\rm 25^\circ C$ .

The product of ${\rm [H^{+}]}$ and ${\rm [OH^{-}]}$ in a solution (with $\rm M$ , or moles per liter, as the unit) is supposed to be equal to the $K_{\rm w}$ value of that solution at the corresponding temperature. In other words:

${\rm [H^{+}]} \cdot {\rm [OH^{-}]} = K_{\rm w}$ .

Rearrange to obtain an expression for ${[\rm OH^{-}]}$ :

$\begin{aligned}{\rm [OH^{-}]} &= \frac{K_{\rm w}}{[\rm H^{+}]}\end{aligned}$ .

Assume that the solution in this question is at $\rm 25^\circ C$ (for which $K_{\rm w} =10^{-14}$ .) For this solution:

$\begin{aligned}{\rm [OH^{-}]} &= \frac{K_{\rm w}}{[\rm H^{+}]} \\ &= \frac{10^{-14}}{2.6 \times 10^{-6}}\approx 3.85\times 10^{-9}\; \rm M\end{aligned}$ .

Hence, the $\rm pOH$ of this solution would be:

$\begin{aligned}\rm pOH &= -\log_{10}{\rm [OH^{-}]} \\&\approx -\log_{10} (3.85 \times 10^{-9}) \approx 8.41 \end{aligned}$ .

3 0

3 years ago