The density of piece of wood will remain the same regardless of its temperature true or false

The forensic technician at a crime scene has just prepared a luminol stock solution by adding 15.0 gg of luminol into a total vo

Firdavs [7]

Answer:

1.13 M

Explanation:

Given data

Mass of luminol (solute): 15.0 g

Volume of solution = volume of water = 75.0 mL = 0.0750 L

Molar mass of luminol: 177.16 g/mol

The molarity of the stock solution of luminol is:

M = mass of solute / molar mass of solute × liters of solution

M = 15.0 g / 177.16 g/mol × 0.0750 L

M = 1.13 M

6 0

3 years ago

10. For the following isotopes that have missing information, fill in the missing informatic

svlad2 [7]

Answer:

Krypton.

Explanation:

Krypton is an atom which has 36 protons in its nucleus. There are 31 isotopes of Krypton which have same number of protons i. e. 36, same number of electrons i. e. 36 but different number of neutrons. Isotope refers to those atoms having same atomic number i. e. number of proton but different mass number i. e. number of neutron. For example, in Krypton-78, there 36 protons and 42 neutrons.

7 0

3 years ago

Carbonic acid, H2CO3, has two acidic hydrogens. A solution containing an unknown concentration of carbonic acid is titrated with

stepan [7]

Answer:

1) Net ionic equation :

$2H^+(aq)+2OH^-(aq)\rightarrow 2H_2O(l)$

2) 0.765 M is the molarity of the carbonic acid solution.

Explanation:

1) In aqueous carbonic acid , carbonate ions and hydrogen ion is present.:

$H_2CO_3(aq)\rightarrow 2H^+(aq)+CO_3^{2-}(aq)$ ..[1]

In aqueous potassium hydroxide , potassium ions and hydroxide ion is present.:

$KOH(aq)\rightarrow K^+(aq)+OH^{-}(aq)$ ..[2]

In aqueous potassium carbonate , potassium ions and carbonate ion is present.:

$K_2CO_3(aq)\rightarrow 2K^+(aq)+CO_3^{2-}(aq)$ ..[3]

$H_2CO_3(aq)+2KOH(aq)\rightarrow K_2CO_3(aq)+2H_2O(l)$

From one:[1] ,[2] and [3]:

$2H^+(aq)+CO_3^{2-}(aq)+2K^+(aq)+2OH^{-}(aq)\rightarrow 2K^+(aq)+CO_3^{2-}(aq)+H_2O(l)$

Cancelling common ions on both sides to get net ionic equation :

$2H^+(aq)+2OH^-(aq)\rightarrow 2H_2O(l)$

2)

To calculate the concentration of acid, we use the equation given by neutralization reaction:

$n_1M_1V_1=n_2M_2V_2$

where,

$n_1,M_1\text{ and }V_1$ are the n-factor, molarity and volume of acid which is $H_2CO_3$

$n_2,M_2\text{ and }V_2$ are the n-factor, molarity and volume of base which is KOH.

We are given:

$n_1=2\\M_1=?\\V_1=50.0 mL\\n_2=1\\M_2=3.840 M\\V_2=20.0 mL$

Putting values in above equation, we get:

$M_1=\frac{1\times 3.840 M\times 20.0 mL}{2\times 50.2 mL}=0.765 M$

0.765 M is the molarity of the carbonic acid solution.

6 0

3 years ago

Scientists use this technology to map the human genome.

pychu [463]

The scientists research project with the goal of determining the sequence of chemical base pairs which make up human DNA, and of identifying and mapping<span> all of the genes of </span>the human genome<span> </span>

4 0

3 years ago

Read 2 more answers

What in the world is the answers

S_A_V [24]

There is a website for this, when I was in 7th grade I had a paper that looked exactly like this, just look up the answers until you find a website for it.

5 0

3 years ago