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Svetradugi [14.3K]

3 years ago

5

What do many scientists believe contributed to the extinction of the dinosaurs? Question 1 options: global warming plate tectoni

cs predators asteroid impact

1 answer:

lesya [120]3 years ago

7 0

Asteroid impact. Most of them believe that it was a large asteroid plunging into what is now the Gulf of Mexico.

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At one point in your life, you might have played on a swing. Have you ever wondered why, after the first swing, it will slow dow

cestrela7 [59]

Answer:

at the top of the swing

at the top of the swing

at the bottom of the swing

at the bottom of the swing

Explanation:

7 0

3 years ago

Nicotine, a component of tobacco, is composed of c, h, and n. a 4.725 −mg sample of nicotine was combusted, producing 12.818 mg

ehidna [41]

C = 12.818 mg CO2 (1 mmol CO2/44 mg CO2) (1 mmol C/1 mmol CO2) = 0.29 mmol

H = 3.675 mg of H2O (1 mmol H2O/18 mg H2O) (2 mmol H/1 mmol H2O) = 0.41 mmol

N = (4.725 mg – 0.29 * 12 – 0.41 * 1) * (1 mmol/14 mg) = 0.06 mmol

Divide everything by the smallest number:

C = 0.29/0.06 = 4.8 ~ 5

<span>H = 0.41/0.06 = 6.8 ~ 7</span>

N = 0.06/0.06 = 1

Empirical formula is:

<span>C5H7N</span>

6 0

3 years ago

Could someone help me balance this chemical equation please

Softa [21]

Balanced equation:
Ca(OH)2+H2SO4=CaSO4+2 H20<span />

4 0

3 years ago

A 25.0-mL sample containing Cu2+ gave an instrument signal of 25.2 units (corrected for a blank). When exactly 0.500 mL of 0.027

irga5000 [103]

Answer:

The molar concentration of Cu²⁺ in the initial solution is 6.964x10⁻⁴ M.

Explanation:

The first step to solving this problem is calculating the number of moles of Cu(NO₃)₂ added to the solution:

$C = \frac{n}{V} \\0.0275 = \frac{n}{0.0005} \\$

n = 1.375x10⁻⁵ mol

The second step is relating the number of moles to the signal. We know the the n calculated before is equivalent to a signal increase of 19.9 units (45.1-25.2):

1.375x10⁻⁵ mol _________ 19.9 units

x _________ 25.2 units

x = 1.741x10⁻⁵mol

Finally, we can calculate the Cu²⁺ concentration :

C = 1.741x10⁻⁵mol / 0.025 L

C = 6.964x10⁻⁴ M

7 0

4 years ago

1. empirical formula for Cu2o4?

Wittaler [7]

We know that

1) empirical formula of a compound is the representation of a molecules with the elements in simplest mole ratio.

2) the molar mass is the actual proportion of moles of elements present in a molecule

3) there is a simple ratio between the molar mass and empirical mass a molecule

Now let us solve each problem

1) empirical formula of $Cu_{2}O_{4}$ will be $CuO_{2}$

2) empirical formula of $Zn_{3}(NO_{3})_{4}$ will be $Zn_{3}(NO_{3})_{4}$

3) empirical formula of $Ti_{2}S_{2.5}$ will be $Ti_{4}S_{5}$

4) the molecular formula will be :

$Ratio=\frac{molarmass}{empiricalformula}=\frac{112.04}{28.01}=4$

the molecular formula = 4 X empirical formula = 4 X CO = $C_{4}O_{4}$

5) the mole ratio of Cl and Cr is $\frac{1.90}{0.631}=3$

empirical formula will be $CrCl_{3}$

6 0

3 years ago