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2 years ago

Which of the following groups of chemical elements would you expect to be most alike in their physical and chemical properties?

1 answer:

8 0

Many elements show very strong similarities to each other.For example, lithium (Li), sodium (Na), and potassium (K) are all soft, very reactive metals.

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PH + pOH = 14. What is the hydroxide concentration of a solution with pH of 8?

sladkih [1.3K]

PH + pOH = 14
pOH=14-8=4
(OH-)=10^-4

4 0

3 years ago

If you added 15,000 calories to 2.0 L of water that was at 25.0 degrees C, what temperature would it be at when you finished?

rewona [7]

Answer:

When we finish, the temperature would be 32.5℃

Explanation:

Density of water = mass/volume

So,

Mass of water = Density × Volume

$\\\\$=1.0 \times 2.0 L$\\\\$=1.0 \frac{g}{m L} \times 2000 m L$\\\\$\quad=2000 g$$

$Q=m \times c \times \Delta T$

where

$\Delta T$ = Final T - Initial T

Q is the heat energy in calories

c is the specific heat capacity (for water 1.0 cal/(g℃))

m is the mass of water

plugging in the values

$15000 \mathrm{Cal}=2000 \mathrm{g} \times 1.0 \frac{\mathrm{cal}}{\mathrm{g}^{\circ} \mathrm{C}} \times \Delta T$

$\\$\Delta T=\frac{15000 \mathrm{cal}}{2000 \mathrm{g} \times \frac{1.0 \mathrm{cal}}{g^{\circ} \mathrm{C}}}$\\\\$\Delta T=7.5^{\circ} \mathrm{C}$$

Final T = ∆T + Initial T

= 7.5℃ + 25℃ = 32.5℃ (Answer).

5 0

2 years ago

When copper is changed to copper(II) nitrate by the nitric acid, it is an example of a(n) ______-_______ reaction. (two words, i

Nataly_w [17]

Answer:

oxidation- reduction

Explanation:

where gaining electronic reduces one element and losing them oxidize the other nitric acid is not only strong it is also a oxidizing agent

<h2>Oxidize: copper = Cu+2</h2>

5 0

2 years ago

Why this process is called a cycle

Greeley [361]

because it is a pattern; airgo cycle

5 0

2 years ago

Read 2 more answers

In NMR if a chemical shift(δ) is 211.5 ppm from the tetramethylsilane (TMS) standard and the spectrometer frequency is 556 MHz,

Vika [28.1K]

Answer:

The answer is: 11759 Hz

Explanation:

Given: Chemical shift: δ = 211.5 ppm, Spectrometer frequency = 556 MHz = 556 × 10⁶ Hz

In NMR spectroscopy, the chemical shift (δ), expressed in ppm, of a given nucleus is given by the equation:

$\delta (ppm) = \frac{Observed\,frequency (Hz)}{Frequency\,\, of\,\,the\,Spectrometer (MHz)} \times 10^{6}$

$\therefore Observed\,frequency (Hz)= \frac{\delta (ppm)\times Frequency\,\, of\,\,the\,Spectrometer (MHz)}{10^{6}}$

$Observed\,frequency= \frac{211.5 ppm \times 556 \times 10^{6} Hz}{10^{6}} = 11759 Hz$

Therefore, the signal is at 11759 Hz from the TMS.

6 0

3 years ago