1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
Anuta_ua [19.1K]
3 years ago
11

Jose’s lab instructor gives him a solution of sodium phosphate that is buffered to a pH of 4. Because of an error that he made w

hile calibrating the pH meter, Jose’s measurements of the pH of the sodium phosphate solution are 5.4, 5.4, and 5.4. what statement best describes his results
Chemistry
1 answer:
RoseWind [281]3 years ago
3 0
His measurements are precise since his pH values are close to each other in a way that it was repeated in all measurements. On the contrary to accuracy, it is the closeness to the actual pH value he should have achieved. Therefore, Jose's results are precise but not accurate since his value is not close to the actual value of pH 4.
You might be interested in
What do cations and anions form?
melomori [17]

Answer: Cations (positively-charged ions) and anions (negatively-charged ions) are formed when a metal loses electrons, and a nonmetal gains those electrons. The electrostatic attraction between the positives and negatives brings the particles together and creates an ionic compound, such as sodium chloride.

7 0
3 years ago
How many moles of Cu(OH)2 are soluble in 1L of sodium hydroxide (NaOH) when the pH is 8.23?
Morgarella [4.7K]

Answer:

4.96E-8 moles of Cu(OH)2

Explanation:

Kps es the constant referring to how much a substance can be dissolved in water. Using Kps, it is possible to know the concentration of weak electrolytes. Then, pKps is the minus logarithm of Kps.

Now, we know that sodium hydroxide (NaOH) is a strong electrolyte, who is completely dissolved in water. Therefore the pH depends only on OH concentration originating from NaOH. Let us to figure out how much is that OH concentration.

pH= -log[H]\\pH= -log (\frac{kw}{[OH]})

8.23 = - log(\frac{Kw}{[OH]} \\10^{-8.23} = Kw/[OH]\\ [OH] = Kw/10^{-8.23}

[OH]=1.69E-6

This concentration of OH affects the disociation of Cu(OH)2. Let us see the dissociation reaction:

Cu(OH)_2 -> Cu^{2+} + 2OH^-

In the equilibrum, exist a concentration of OH already, that we knew, and it will be added that from dissociation, called "s":

The expression for Kps is:

Kps= [Cu^{2+}] [OH]^2

The moles of (CuOH)2 soluble are limitated for the concentration of OH present, according to the next equation.

Kps= s*(2s+1.69E-6)^2

"s" is the soluble quantity of Cu(OH)2.

The solution for this third grade equation is s=4.96E-8 mol/L

Now, let us calculate the moles in 1 L:

moles Cu(OH)_2 = 4.96E-8 mol/L * 1 L = 4.96E-8 moles

7 0
3 years ago
what gas was given off when hydrogen peroxide is broken down? recall that the formula for hydrogen peroxide is h2o2?
Anna35 [415]
When hydrogen peroxide is broken down the gas released or given off is Oxygen. 
5 0
3 years ago
How many total phosphorus atoms are shown in the following: Al2P3? *
Wewaii [24]

Answer:

3 P atoms

Explanation:

Al₂P₃ => contains 2 Aluminum ions (2Al⁺³) and 3 Phosphide ions (3P⁻³) ... The ions (charged particles) are from atoms that have lost or gained electrons during the bonding process. So, Al₂P₃ => P⁻³ ions from 3 P atoms.

6 0
3 years ago
What mass of natural gas (CH4) must you burn to emit 264 kJ of heat?
mariarad [96]
The heat released by cpmolete the combustion of organic products with oxygen is called heat of combustion.

Here 1 mol of CH4 realesed 802.3 KJ

To emit 264 kJ you multiply you need (1 mol of CH4/802.3 kJ)* 264 kJ = 0.329 mol of CH4

The molar mass, MM, of CH4 is 12 g/mol + 4*1g/mol = 16 g/mol

The to obtain the mass multiply the number of moles times the molar mass:

mass = n * MM = 0.329mol * 16g/mol = 5.26 grams

Answer: 5.26 grams



7 0
3 years ago
Other questions:
  • When vinegar and baking soda are combined what bubbles form
    15·1 answer
  • The atomic mass of an element is the ____. ) total number of subatomic particles in its nucleus
    14·1 answer
  • Alcohol is poured into a beaker that contains 2% saltwater. Which are the solutes in the new solution?
    8·2 answers
  • How many kJ of heat are released by the reaction of 25.0 g of Na2O2(s) in the following reaction? (M = 78.0 g/mol for Na2O2)
    7·1 answer
  • Carbon monoxide and chlorine gas react to form phosgene:
    13·1 answer
  • Which substance has the most thermal energy and will have the most heat flow from it?
    8·2 answers
  • The struggle for existence against other members of an organisms species is
    7·2 answers
  • Use the balanced equation given below to solve the problem that follows: Calculate the mass in grams of water produced along wit
    13·1 answer
  • A sample of radioactive waste has a half-live of 40 years and an activity level of 4 curies. After how many years will the activ
    9·1 answer
  • if a gas has an initial pressure of 24,650 pa and an initial volume of 376 ml, what is the final volume if the pressure of the g
    10·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!