1. In 1897, I made a beam of electrons in a vacuum tube. Who

Consider these phylogenetic trees. The first tree is based on physical characteristics. The second tree is based on structure, g

kati45 [8]

Im not 100% sure, but I think the answer is C. If not, Im sorry for bothering you.

7 0

3 years ago

Read 2 more answers

Complete and balance each of the following equations for gas evolution reactions HCl(aq)+ZnS(s)>

DENIUS [597]

2HCl(aq) + ZnS(s) ⇒ ZnCl₂(aq) + H₂S(g)

<h3>Further explanation </h3>

Equalization of chemical reactions can be done using variables. Steps in equalizing the reaction equation:

1. gives a coefficient on substances involved in the equation of reaction such as a, b, or c, etc.
2. make an equation based on the similarity of the number of atoms where the number of atoms = coefficient × index (subscript) between reactant and product
3. Select the coefficient of the substance with the most complex chemical formula equal to 1

Reaction

HCl(aq) + ZnS(s) ⇒ ZnCl₂(aq) + H₂S(g)

1. give equation

aHCl(aq) + bZnS(s) ⇒ ZnCl₂(aq) + cH₂S(g)

2. make an equation

H, left=a, right=2c⇒a=2c(eq 1)

Cl, left=a, right=2⇒a=2⇒c=1(from eq 1)

Zn, left=b, right=1⇒b=1

So the equation :

2HCl(aq) + ZnS(s) ⇒ ZnCl₂(aq) + H₂S(g)

4 0

3 years ago

Somebody help me asap please giving brainliest

Serggg [28]

Answer:

fire > rocks > air

3 0

3 years ago

I need a real life example when you need to know about viscosity. <br> Thanks!!

NemiM [27]

Viscosity refers to a fuilds resistance to flow.

EX: Honey have higher viscosity than water.

7 0

3 years ago

How many moles of chromium III nitrate are produced When chromium reacts with 0.85 moles of lead for nitrate to produce chromium

Pepsi [2]

0.85 moles formula units of lead nitrate will produce 0.57 moles formula units of chromium (III) nitrate.

<h3>Explanation</h3>

Typically, the oxidation state of Pb in lead nitrate tend to be +2. In other words, Pb in lead nitrate tends to exist as $\text{Pb}^{2+}$ ions. The formula for a nitrate ion is ${\text{NO}_3}^{-}$ . The charge on each of the nitrate ion is -1. The charge on the two ions should balance. As a result, each $\text{Pb}^{2+}$ ion in lead nitrate would pair up with two ${\text{NO}_3}^{-}$ ions. The formula for lead nitrate will be $\text{Pb}({\text{NO}_3})_2$ . Each formula unit of lead nitrate will contain one $\text{Pb}^{2+}$ ion and two ${\text{NO}_3}^{-}$ ions.

The "III" in the name "chromium (III) nitrate" is a Roman Numeral. It indicates that the oxidation state of Cr in chromium (III) nitrate is +3. The Cr in that compound will exist as $\text{Cr}^{3+}$ . Similarly, each $\text{Cr}^{3+}$ will pair up with three ${\text{NO}_3}^{-}$ ions. The formula for chromium (III) nitrate will be $\text{Cr}(\text{NO}_3})_3$ . Each formula unit of chromium (III) nitrate will contain one ${\text{NO}_3}^{-}$ ion and three ${\text{NO}_3}^{-}$ ions.

0.85 moles formula units of lead nitrate will contain 0.85 × 2 = 1.7 moles of ${\text{NO}_3}^{-}$ ions. Those nitrate ions will end up in 1.7 / 3 = 0.57 moles formula units of chromium (III) nitrate. As a result, the reaction will produce 0.57 moles formula units of chromium (III) nitrate.

7 0

3 years ago