From the image shown, the uncertainty in the weighing balance extends to the hundredth place.
<h3>What is a balance?</h3>
A balance is any device that is used for measuring the mass or weight of an object. The balance is a necessary instrument in every laboratory.
Looking at the image shown, the following are true;
- the uncertainty is in the hundredth place.
- a mass that falls between 1 gram and 9 grams measured on this balance will always have 3 significant figures.
Learn more about weighing balance: brainly.com/question/8902159
Answer:
a, and f.
Explanation:
To be deprotonated, the conjugate acid of the base must be weaker than the acid that will react, because the reactions favor the formation of the weakest acid. The pKa value measures the strength of the acid. As higher is the pKa value, as weak is the acid. So, let's identify the conjugate acid and their pKas:
a. NaNH2 will dissociate, and NH2 will gain the proton and forms NH3 as conjugate acid. pKa = 38.0, so it happens.
b. NaOH will dissociate, and OH will gain the proton and forms H2O as conjugate acid. pKa = 14.0, so it doesn't happen.
c. NaC≡N will dissociate, and CN will gain a proton and forms HCN as conjugate acid. pKa = 9.40, so it doesn't happen.
d. NaCH2(CO)N(CH3)2 will dissociate and forms CH3(CO)N(CH3)2 as conjugate acid. pKa = -0.19, so it doesn't happen.
e. H2O must gain one proton and forms H3O+. pKa = -1.7, so it doesn't happen.
f. CH3CH2Li will dissociate, and the acid will be CH3CH3. pKa = 50, so it happens.
In 0.190 mole of C6H14O, there is 0.190*6 (number of C in one molecule) = 1.140 mole of C atoms. The total number of C atoms = 1.14 * 6*
(atoms of C in one mole) = 6.84*
atoms.
Answer:
D. chlorine, oxygen, nitrogen, hydrogen.
Explanation:
- Thomas Graham found that, at a constant temperature and pressure the rates of effusion of various gases are inversely proportional to the square root of their masses.
<em>ν ∝ 1/√M</em>
where ν is the rate of effusion and M is the atomic or molecular mass of the gas particles.
- The molecular mass for the listed gases are:
O₂: 32.0 g/mol,
Cl₂: 70.906 g/mol,
N₂: 28.0 g/mol,
H₂: 2.0 g/mol.
- Hence, the smallest molecular mass of the gas, the fastest rate of effusion.
So, the order from the slowest to the fastest rate of effusion is:
<em>Chlorine, oxygen, nitrogen, hydrogen.</em>
Answer: 2 (2 neutrons are produced).
Explanation:
1) In the left side of the transmutation equationa appears:
²³⁵U + ¹n →
I am omitting the atomic number (subscript to the leff) because the question does not show them as it is focused on number of neutrons.
2) The right side of the transmutation equation has:
→ ¹⁴⁴Ce + ⁹⁰Sr + ?
3) The total mass number of the left side is 235 + 1 = 236
4) The total mass number of Ce and Sr on the right side is 144 + 90 = 234
5) Then, you are lacking 236 - 234 = 2 unit masses on the right side which are the 2 neutrons that are produced along with the Ce and Sr.
The complete final equation is:
²³⁵U + ¹n → ¹⁴⁴Ce + ⁹⁰Sr + 2 ¹n
Where you have the two neutrons produced.
