All categories

3 years ago

When does heat naturally move from cooler objects to warmer objects

1 answer:

8 0

<span>Conduction occurs when two object at different temperatures are in contact with each other. Heat flows from the warmer to the cooler object until they are both at the same temperature. Conduction is the movement of heat through a substance by the collision of molecules. At the place where the two object touch, the faster-moving molecules of the warmer object collide with the slower moving molecules of the cooler object. </span>

You might be interested in

What are the coordinates of the midpoint of the line segment with endpoints (2, 5) and (4, -7)?

Lena [83]

Answer:

(3,2)

Explanation:

The x-co-ordinates above are 2 and 4

Their midpoint is 2+4/2

The y-co-ordinates above are 5 and -1

Their midpoint is 5+(-1)/2 = 2

The overall midpoint is (3,2)

6 0

3 years ago

The pKa of lactic acid is 3.9. A lactate buffer will be useful from pH values ________. The pKa of lactic acid is 3.9. A lactate

Vedmedyk [2.9K]

Answer:

Explanation:

The usefulness of a buffer is its ability to resist changes in pH when small quantities of base or acid are added to it. This ability is the consequence of having both the conjugate base and the weak acid present in solution which will consume the added base or acid.

This capacity is lost if the ratio of the concentration of conjugate base to the concentration of weak acid differ by an order of magnitude. Since buffers having ratios differing by more will have their pH driven by either the weak acid or its conjugate base .

From the Henderson-Hasselbach equation we have that

pH = pKa + log [A⁻]/[HA]

thus

0.1 ≤ [A⁻]/[HA] ≤ 10

Therefore the log of this range is -1 to 1, and the pH will have a useful range of within +/- 1 the pKa of the buffer.

Now we are equipped to answer our question:

pH range = 3.9 +/- 1 = 2.9 through 4.9

7 0

3 years ago

How many moles are in 3.24 x 1020 particles of lead? (show work plz)

lesya [120]

<h3>Answer:</h3>

0.000538 mol Pb

<h3>General Formulas and Concepts:</h3>

<u>Math</u>

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right<u> </u>

<u>Chemistry</u>

<u>Atomic Structure</u>

Avogadro's Number - 6.022 × 10²³ atoms, molecules, formula units, etc.

<u>Stoichiometry</u>

Using Dimensional Analysis

<h3>Explanation:</h3>

<u>Step 1: Define</u>

3.24 × 10²⁰ particles Pb (lead)

<u>Step 2: Identify Conversions</u>

Avogadro's Number

<u>Step 3: Convert</u>

Set up: $\displaystyle 3.24 \cdot 10^{20} \ particles \ Pb(\frac{1 \ mol \ Pb}{6.022 \cdot 10^{23} \ particles \ Pb})$
Multiply/Divide: $\displaystyle 0.000538 \ mol \ Pb$

<u>Step 4: Check</u>

<em>Follow sig fig rules and round. We are given 3 sig figs.</em>

Our final answer is in 3 sig figs, no need to round.

7 0

3 years ago

Why are there 24 hours in 1 day?

LuckyWell [14K]

Answer:

idfk

Explanation:

cause God made it that way

3 0

3 years ago

Read 2 more answers

Plz help me i swear will mark you brainiest :(

vladimir1956 [14]

Answer:

C. the relative molecular mass of the compound

Explanation:

Like molecular formulas, empirical formulas are not unique and can describe a number of different chemical structures or isomers. <u>To determine an empirical formula, the relative molecular mass of the composition of its elements</u> can be used to mathematically determine their ratio.

7 0

2 years ago