Química
- Equilíbrio Químico
- Prova de 2019
- CEDERJ
- Dificuldade: Difícil
- Código da questão: 711FF47D-8B
Instituição
1.157 questões de Centro de Educação Superior a Distância do Estado do Rio de Janeiro (CEDERJ), de 2006 a 2025. Cada uma tem página própria, com enunciado completo, alternativas e gabarito — e dá para responder na própria página.
Fake news could ruin social media, but there’s still hope
by: Guðrun í Jákupsstovu
Camille Francois, director of research and analysis at Graphika, told the audience of her talk at TNW Conference:
“Disinformation campaigns, or fake news is a concept we’ve known about for years, but few people realize how varied the concept can be and how many forms it comes in. When the first instances of fake news started to surface, they were connected with bots. These flooded conversations with alternative stories in order to create noise and, in turn, silence what was actually being said”.
According to Francois, today’s disinformation campaigns are far more varied than just bots – and much harder to detect. For example, targeted harassment campaigns are carried out against journalists and human-rights activists who are critical of governments or big organizations.
“We see this kind of campaigns happening at large scale in countries like the Philippines, Turkey, Ecuador, and Venezuela. The point of these campaigns is to flood the narrative these people try to create with so much noise that their original message gets silenced, their reputation gets damaged, and their credibility undermined. I call this patriotic trolling.”
There are also examples of disinformation campaigns mobilizing people. This was evident during the US elections in 2016 when many fake events suddenly started popping up on Facebook. One Russian Facebook page “organized” an anti-Islam event, while another “organized” a pro-Islam demonstration. The two fake events gathered activists to the same street in Texas, leading to a stand-off.
Francois explains how amazed she is that, in spite of social media being the main medium for these different disinformation campaigns, actual people also still use it to protest properly.
If we look at countries, like Turkey – where there’s a huge amount of censorship and smear campaigns directed at human right defenders and journalists – citizens around the world and in those places still use social media to denounce corruption, to organize human rights movements and this proves that we still haven’t lost the battle of who owns social media.
This is an ongoing battle, and it lets us recognize the actors who are trying to remove the option for people to use social media for good. But everyday you still have people all over the world turning to social media to support their democratic activities. This gives me hope and a desire to protect people’s ability to use social media for good, for denouncing corruption and protecting human rights.
Adapted from:<https://thenextweb.com/socialmedia/2018/05/25/> . Access 09 Oct. 2018.
Glossary
bot: (short for "robot"): um programa automático que roda
na Internet; to flood: inundar; trolling: fazer postagem deliberadamente ofensiva para provocar alguém; popping up:
surgir, aparecer; stand-off: impasse: smear campaigns:
campanhas de difamação.
Muitos dos protetores solares disponíveis no mercado contêm duas substâncias químicas: a oxibenzona e o octinoxato. Estudos científicos realizados em laboratório associam essas substâncias a problemas de reprodução e de branqueamento de corais, o que os deixa enfraquecidos e, com o tempo, os leva à morte. Em 2016, uma equipe de cientistas americanos relatou que essas substâncias poderiam interromper o crescimento dos corais. Esses filtros químicos são liberados pela pele humana à medida que as pessoas mergulham, nadam ou surfam no mar.
Considere as fórmulas estruturais planas:

Em relação a essas moléculas, é correto afirmar que
Sejam p e q números inteiros.
A sentença verdadeira é:

A calcinação de 2.8400 g de uma mistura sólida constituída de CaCO3 e MgCO3 produziu um gás e um resíduo sólido de peso 1.5200 g.
Com essas informações, é correto afirmar que
Dois satélites percorrem órbitas circulares em torno da Terra. Os raios das suas órbitas são R1 e R2 e suas velocidades escalares correspondentes são v1 e v2.
Sabendo-se que v2 = 2v1, a relação entre R2 e R1 é:
A cientista americana Lynn Margulis ficou conhecida por sua teoria da endossimbiose, que desafia as teorias neodarwinistas com o argumento de que as variações herdadas não se devem a mutações ao acaso, mas à interação entre os organismos a longo prazo. Segundo Margulis, a origem das primeiras células com núcleo se deu a partir da fusão de bactérias primitivas, há bilhões de anos, e essa associação seria um fator a ser levado em conta na evolução das células eucarióticas.
Segundo essa teoria,
Texto 2
Campeonato de peão
Bota parafuso no bico do peão
Bota prego limado, bota tudo
pra rachar o pião competidor.
Roda, pião!
Racha, pião!
Se você não pode rachar este colégio
nem o mundo nem a vida,
racha pelo menos o pião!
(Mas eu não sei, nunca aprendi
rachar pião. Imobilizo-me.)
(Carlos Drummond de Andrade. Nova reunião: 23 livros de poesia. Vol. III.
Rio de Janeiro, Bestbolso, 2009. p.267)
Tem-se a seguinte célula: Mn2+ (0.1 M) + O2 (1 atm) + 2H2O ⇄ MnO2 + H2O2 (0.1 M) + 2H+ (0.1 M).
Considere que na temperatura ambiente os valores dos potenciais padrão das espécies constituintes da célula, são:
O2 + 2H+ + 2e− ⇄ H2O2 E0 = + 0.68 V
MnO2 + 4H+ + 2e− ⇄ Mn2+ + 2H2O E0 = + 1.23 V
A direção que a reação vai tomar e o potencial
gerado são respectivamente:
Text 1
The global warming controversy
The global warming controversy is an ongoing dispute about the effects of humans on global climate and about what policies should be implemented to avoid possible undesirable effects of climate change.
The current scientific consensus on climate change is that recent warming indicates a fairly stable long-term trend, that the trend is largely human-caused, and that serious damage may result at some future date if steps are not taken to halt the trend.
Mainstream scientific organizations worldwide (Royal Society, American Geophysical Union, Joint Science Academies, Intergovernmental Panel on Climate Change, American Meteorological Society, and American Association for the Advancement of Science) concur with the assessment that most of the observed warming over the last 50 years is likely to have been due to the human-caused increase in greenhouse gas concentrations.
However, there is also a small but vocal number of scientists in climate and climate-related fields that disagree with the consensus view.
Adapted from:< https://www.sciencedaily.com/terms/global_warming_controversy.htm.> Access 30 Sept. 2017.
Text 2
Climate change label leads to climate science acceptance
On the heels of President Donald Trump's decision to pull the United States out of the Paris climate agreement, a new Cornell University study finds that labels matter when it comes to acceptance of climate science.
The U.S. public doubts the existence of "global warming" more than it doubts "climate change".
In a nationally representative survey, 74.4 percent of respondents said they believed that climate change is really happening. But only 65.5 percent said they believed in global warming.
Nonetheless, it's important to remember that 65 percent of respondents did indicate that global warming is occurring, said co-author Peter Enns, associate professor of government. "In other words, although the term matters -- climate change versus global warming -- an overwhelming majority of people still state that global warming is happening," he said.
Adapted from:<http://mediarelations.cornell.edu/2017/06/21/climate-change-label-leads-to-climate-science-acceptance/>. Access. 23 Sept. 2017.
Glossário
Text 1
The global warming controversy
The global warming controversy is an ongoing dispute about the effects of humans on global climate and about what policies should be implemented to avoid possible undesirable effects of climate change.
The current scientific consensus on climate change is that recent warming indicates a fairly stable long-term trend, that the trend is largely human-caused, and that serious damage may result at some future date if steps are not taken to halt the trend.
Mainstream scientific organizations worldwide (Royal Society, American Geophysical Union, Joint Science Academies, Intergovernmental Panel on Climate Change, American Meteorological Society, and American Association for the Advancement of Science) concur with the assessment that most of the observed warming over the last 50 years is likely to have been due to the human-caused increase in greenhouse gas concentrations.
However, there is also a small but vocal number of scientists in climate and climate-related fields that disagree with the consensus view.
Adapted from:< https://www.sciencedaily.com/terms/global_warming_controversy.htm.> Access 30 Sept. 2017.
Text 2
Climate change label leads to climate science acceptance
On the heels of President Donald Trump's decision to pull the United States out of the Paris climate agreement, a new Cornell University study finds that labels matter when it comes to acceptance of climate science.
The U.S. public doubts the existence of "global warming" more than it doubts "climate change".
In a nationally representative survey, 74.4 percent of respondents said they believed that climate change is really happening. But only 65.5 percent said they believed in global warming.
Nonetheless, it's important to remember that 65 percent of respondents did indicate that global warming is occurring, said co-author Peter Enns, associate professor of government. "In other words, although the term matters -- climate change versus global warming -- an overwhelming majority of people still state that global warming is happening," he said.
Adapted from:<http://mediarelations.cornell.edu/2017/06/21/climate-change-label-leads-to-climate-science-acceptance/>. Access. 23 Sept. 2017.
Glossário
Com base nas informações sobre os valores de potenciais de redução, a 25º C:
Mg+2(aq) + 2 e- ⇄ Mg (s) E° = - 2.4 V
Cu+2(aq) + 2 e- ⇄ Cu (s) E° = + 0.34 V
É correto afirmar que:
A figura mostra duas partículas A e B de massas respectivamente iguais a mA e mB e cargas elétricas qA e qB. Considere que elas estão sujeitas exclusivamente às forças eletrostáticas mútuas devidas às suas cargas e que as setas na figura representam suas respectivas acelerações vetoriais:

Comparando as cargas e as massas das partículas,
conclui-se que