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3 years ago

Help pls true or false

Chemistry

1 answer:

makvit [3.9K]3 years ago

7 0

Answer:

1 oxygen from the lungs

Explanation:

maybe too help you breath better

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Nonferrous alloys do not contain a. copper. b. brass. c. gold. d. iron.

marin [14]

Nonferrous alloys do not contain iron as the name suggests. Ferrous is the latin word for iron. These alloys use precious metals such as gold, silver, platinum and other metals like copper, aluminum, lead, zinc and even alloys like brass. Answer is D.

6 0

3 years ago

Which elements are out of order in terms of atomic mass. co,Ni or Li,be or I,xe

valkas [14]

Answer:

The pair co,Ni is out of order in terms of atomic mass

Explanation:

For co,Ni

Atomic mass of Co = 58.9331 u

Atomic mass of Ni = 58.6934

For Li,be

Atomic mass of Li = 6.941 u

Atomic mass of be = 9.012182 u

For I,xe

Atomic mass of I = 126.90447 u

Atomic mass of Xe = 131.293 u

Hence, the pair co,Ni is out of order in terms of atomic mass

7 0

3 years ago

H2O+O2=H202, how would I balance this equation?

Sergio [31]

Answer:

2H2O2→2H2O+O2

Explanation:

This reaction is of the spontaneous decomposition of hydrogen peroxide down into water and oxygen.

Add 2 molecules of hydrogen peroxide and 2 molecules of water. Since oxygen is naturally diatomic, the total number of atoms of each element is now the same on both sides of the equation so it is balanced.

2H2O2→2H2O+O2

8 0

3 years ago

You have to prepare 100.0 mL of a 0.100 M solution of sodium carbonate. You have a concentrated solution of sodium carbonate tha

Georgia [21]

Answer:

6.9 ml of concentrate

Explanation:

100 ml of .1 M will require .01 moles

from a 1.45 M solution, .01 mole would be

.01 mole / ( 1.45 mole / liter) = 6.9 ml of the concentrate then dilute to 100 ml

4 0

2 years ago

You need to prepare 1 L of the citric acid/citrate buffer. You have chosen to use Method 1 (see lab presentation). Calculate the

prisoha [69]

Answer:

3.11 is the pH of the buffer

Explanation:

The pH of a buffer is obtained using H-H equation:

pH = pKa + log [Conjugate base] / [Weak acid]

Where pH is the pH of the buffer, pKa = -log Ka = 3.14 for the citric buffer and [] could be taken as the moles of each species.

The citric acid,HX (Weak acid), reacts with NaOH to produce sodium citrate, NaX (weak base) and water:

HX + NaOH → H2O + NaX

That means the moles of NaOH added = Moles of sodium citrate produced

And the resulitng moles of HX = Initial moles - Moles NaOH added

Moles HX and NaX:

Moles NaOH = 0.100L * (0.65mol / L) = 0.065 moles NaOH = Moles NaX

Moles HX = 0.300L * (0.45mol / L) = 0.135 moles HX - 0.065 moles NaOH = 0.070 moles HX

Replacing in H-H equation:

pH = 3.14 + log [0.065mol] / [0.070mol]

pH = 3.11 is the pH of the buffer

8 0

3 years ago